Flatspace chiral supergravity

NASA Astrophysics Data System (ADS)

Bagchi, Arjun; Basu, Rudranil; Detournary, Stéphane; Parekh, Pulastya

2018-05-01

We propose a holographic duality between a 2 dimensional (2d) chiral superconformal field theory and a certain theory of supergravity in 3d with flatspace boundary conditions that is obtained as a double scaling limit of a parity breaking theory of supergravity. We show how the asymptotic symmetries of the bulk theory reduce from the "despotic" super Bondi-Metzner-Sachs algebra (or equivalently the inhomogeneous super Galilean conformal algebra) to a single copy of the super-Virasoro algebra in this limit and also reproduce the same reduction from a study of null vectors in the putative 2d dual field theory.

Matter-coupled de Sitter supergravity

NASA Astrophysics Data System (ADS)

Kallosh, R. E.

2016-05-01

The de Sitter supergravity describes the interaction of supergravity with general chiral and vector multiplets and also one nilpotent chiral multiplet. The extra universal positive term in the potential, generated by the nilpotent multiplet and corresponding to the anti-D3 brane in string theory, is responsible for the de Sitter vacuum stability in these supergravity models. In the flat-space limit, these supergravity models include the Volkov-Akulov model with a nonlinearly realized supersymmetry. We generalize the rules for constructing the pure de Sitter supergravity action to the case of models containing other matter multiplets. We describe a method for deriving the closed-form general supergravity action with a given potential K, superpotential W, and vectormatrix fAB interacting with a nilpotent chiral multiplet. It has the potential V = eK(|F2|+|DW|2-3|W|2), where F is the auxiliary field of the nilpotent multiplet and is necessarily nonzero. The de Sitter vacuums are present under the simple condition that |F2|-3|W|2 > 0. We present an explicit form of the complete action in the unitary gauge.

On the formulation of D=11 supergravity and the composite nature of its three-form gauge field

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bandos, Igor A.; Institute for Theoretical Physics, NSC 'Kharkov Institute of Physics and Technology', UA61108, Kharkov; Azcarraga, Jose A. de

2005-05-01

The underlying gauge group structure of the D=11 Cremmer-Julia-Scherk supergravity becomes manifest when its three-form field A{sub 3} is expressed through a set of one-form gauge fields, B1a1a2, B1a1...a5, {eta}{sub 1{alpha}}, and E{sup a}, {psi}{sup {alpha}}. These are associated with the generators of the elements of a family of enlarged supersymmetry algebras E-bar (528 vertical bar 32+32)(s) parametrized by a real number s. We study in detail the composite structure of A{sub 3} extending previous results by D'Auria and Fre, stress the equivalence of the above problem to the trivialization of a standard supersymmetry algebra E(11 vertical bar 32) cohomologymore » four-cocycle on the enlarged E-bar (528 vertical bar 32+32)(s) superalgebras, and discuss its possible dynamical consequences. To this aim we consider the properties of the first order supergravity action with a composite A{sub 3} field and find the set of extra gauge symmetries that guarantee that the field theoretical degrees of freedom of the theory remain the same as with a fundamental A{sub 3}. The extra gauge symmetries are also present in the so-called rheonomic treatment of the first order D=11 supergravity action when A{sub 3} is composite. Our considerations on the composite structure of A{sub 3} provide one more application of the idea that there exists an extended superspace coordinates/fields correspondence. They also suggest that there is a possible embedding of D=11 supergravity into a theory defined on the enlarged superspace {sigma}-bar (528 vertical bar 32+32)(s)« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Tingting; Northeast Petroleum University at Qinhuangdao, Qinhuangdao 066004; Shao, Guangjie, E-mail: shaoguangjie@ysu.edu.cn

A method of pulse electrodeposition under supergravity field was proposed to synthesize MnO{sub 2}-graphene composites. Supergravity is very efficient for promoting mass transfer and decreasing concentration polarization during the electrodeposition process. The synthesis was conducted on our homemade supergravity equipment. The strength of supergravity field depended on the rotating speed of the ring electrode. 3D flower like MnO{sub 2} spheres composed of nanoflakes were acquired when the rotating speed was 3000 rpm. Graphene nanosheets play as a role of conductive substrates for MnO{sub 2} growing. The composites are evaluated as electrode materials for supercapacitors. Electrochemical results show that the maximummore » specific capacitance of the MnO{sub 2}-graphene composite is 595.7 F g{sup −1} at a current density of 0.5 A g{sup −1}. In addition, the composite exhibits excellent cycle stability with no capacitance attenuation after 1000 cycles. The approach provides new ideas for developing supercapacitor electrode materials with high performance. - Graphical abstract: 3D flower like MnO{sub 2} spheres composed of nanoflakes were acquired at 3000 rpm. - Highlights: • MnO{sub 2}-graphene composites were prepared by pulse electrodeposition under supergravity. • 3D flower like MnO{sub 2} spheres are anchored on the graphene nanosheets. • The MnO{sub 2}-graphene electrode exhibits a specific capacitance of 595.7 F g{sup −1}.« less

Brane SUSY breaking and the gravitino mass

NASA Astrophysics Data System (ADS)

Kitazawa, Noriaki

2018-04-01

Supergravity models with spontaneously broken supersymmetry have been widely investigated over the years, together with some notable non-linear limits. Although in these models the gravitino becomes naturally massive absorbing the degrees of freedom of a Nambu-Goldstone fermion, there are cases in which the naive counting of degrees of freedom does not apply, in particular because of the absence of explicit gravitino mass terms in unitary gauge. The corresponding models require non-trivial de Sitter-like backgrounds, and it becomes of interest to clarify the fate of their Nambu-Goldstone modes. We elaborate on the fact that these non-trivial backgrounds can accommodate, consistently, gravitino fields carrying a number of degrees of freedom that is intermediate between those of massless and massive fields in a flat spacetime. For instance, in a simple supergravity model of this type with de Sitter background, the overall degrees of freedom of gravitino are as many as for a massive spin-3/2 field in flat spacetime, while the gravitino remains massless in the sense that it undergoes null-cone propagation in the stereographic picture. On the other hand, in the ten-dimensional USp(32) Type I Sugimoto model with "brane SUSY breaking", which requires a more complicated background, the degrees of freedom of gravitino are half as many of those of a massive one, and yet it somehow behaves again as a massless one.

General N=1 supersymmetric flux vacua of massive type IIA string theory.

PubMed

Behrndt, Klaus; Cvetic, Mirjam

2005-07-08

We derive conditions for the existence of four-dimensional N=1 supersymmetric flux vacua of massive type IIA string theory with general supergravity fluxes turned on. For an SU(3) singlet Killing spinor, we show that such flux vacua exist when the internal geometry is nearly Kähler. The geometry is not warped, all the allowed fluxes are proportional to the mass parameter, and the dilaton is fixed by a ratio of (quantized) fluxes. The four-dimensional cosmological constant, while negative, becomes small in the vacuum with the weak string coupling.

On gauged maximal d  =  8 supergravities

NASA Astrophysics Data System (ADS)

Lasso Andino, Óscar; Ortín, Tomás

2018-04-01

We study the gauging of maximal d  =  8 supergravity using the embedding tensor formalism. We focus on SO(3) gaugings, study all the possible choices of gauge fields and construct explicitly the bosonic actions (including the complicated Chern–Simons terms) for all these choices, which are parametrized by a parameter associated to the 8-dimensional SL(2, {R}) duality group that relates all the possible choices which are, ultimately, equivalent from the purely 8-dimensional point of view. Our result proves that the theory constructed by Salam and Sezgin by Scherk–Schwarz compactification of d  =  11 supergravity and the theory constructed in Alonso-Alberca (2001 Nucl. Phys. B 602 329) by dimensional reduction of the so called ‘massive 11-dimensional supergravity’ proposed by Meessen and Ortín in (1999 Nucl. Phys. B 541 195) are indeed related by an SL(2, {R}) duality even though they have two completely different 11-dimensional origins.

Massive gravity in three dimensions.

PubMed

Bergshoeff, Eric A; Hohm, Olaf; Townsend, Paul K

2009-05-22

A particular higher-derivative extension of the Einstein-Hilbert action in three spacetime dimensions is shown to be equivalent at the linearized level to the (unitary) Pauli-Fierz action for a massive spin-2 field. A more general model, which also includes "topologically-massive" gravity as a special case, propagates the two spin-2 helicity states with different masses. We discuss the extension to massive N-extended supergravity, and we present a "cosmological" extension that admits an anti-de Sitter vacuum.

Separability of massive field equations for spin-0 and spin-1/2 charged particles in the general nonextremal rotating charged black hole spacetimes in minimal five-dimensional gauged supergravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu Shuangqing

We continue to investigate the separability of massive field equations for spin-0 and spin-1/2 charged particles in the general, nonextremal, rotating, charged, Chong-Cvetic-Lue-Pope black holes with two independent angular momenta and a nonzero cosmological constant in minimal D=5 gauged supergravity theory. We show that the complex Klein-Gordon equation and the modified Dirac equation with the inclusion of an extra counterterm can be separated by variables into purely radial and purely angular parts in this general Einstein-Maxwell-Chern-Simons background spacetime. A second-order symmetry operator that commutes with the complex Laplacian operator is constructed from the separated solutions and expressed compactly in termsmore » of a rank-2 Staeckel-Killing tensor which admits a simple diagonal form in the chosen pentad one-forms so that it can be understood as the square of a rank-3 totally antisymmetric tensor. A first-order symmetry operator that commutes with the modified Dirac operator is expressed in terms of a rank-3 generalized Killing-Yano tensor and its covariant derivative. The Hodge dual of this generalized Killing-Yano tensor is a generalized principal conformal Killing-Yano tensor of rank-2, which can generate a 'tower' of generalized (conformal) Killing-Yano and Staeckel-Killing tensors that are responsible for the whole hidden symmetries of this general, rotating, charged, Kerr-anti-de Sitter black hole geometry. In addition, the first laws of black hole thermodynamics have been generalized to the case that the cosmological constant can be viewed as a thermodynamical variable.« less

More on the hidden symmetries of 11D supergravity

NASA Astrophysics Data System (ADS)

Andrianopoli, Laura; D'Auria, Riccardo; Ravera, Lucrezia

2017-09-01

In this paper we clarify the relations occurring among the osp (1 | 32) algebra, the M-algebra and the hidden superalgebra underlying the Free Differential Algebra of D=11 supergravity (to which we will refer as DF-algebra) that was introduced in the literature by D'Auria and Frè in 1981 and is actually a (Lorentz valued) central extension of the M-algebra including a nilpotent spinor generator, Q‧. We focus in particular on the 4-form cohomology in 11D superspace of the supergravity theory, strictly related to the presence in the theory of a 3-form A (3). Once formulated in terms of its hidden superalgebra of 1-forms, we find that A (3) can be decomposed into the sum of two parts having different group-theoretical meaning: One of them allows to reproduce the FDA of the 11D Supergravity due to non-trivial contributions to the 4-form cohomology in superspace, while the second one does not contribute to the 4-form cohomology, being a closed 3-form in the vacuum, defining however a one parameter family of trilinear forms invariant under a symmetry algebra related to osp (1 | 32) by redefining the spin connection and adding a new Maurer-Cartan equation. We further discuss about the crucial role played by the 1-form spinor η (dual to the nilpotent generator Q‧) for the 4-form cohomology of the eleven dimensional theory on superspace.

Gauge and Non-Gauge Tensor Multiplets in 5D Conformal Supergravity

NASA Astrophysics Data System (ADS)

Kugo, T.; Ohashi, K.

2002-12-01

An off-shell formulation of two distinct tensor multiplets, a massive tensor multiplet and a tensor gauge multiplet, is presented in superconformal tensor calculus in five-dimensional space-time. Both contain a rank 2 antisymmetric tensor field, but there is no gauge symmetry in the former, while it is a gauge field in the latter. Both multiplets have 4 bosonic and 4 fermionic on-shell modes, but the former consists of 16 (boson)+16 (fermion) component fields, while the latter consists of 8 (boson)+8 (fermion) component fields.

AdS6 solutions of type II supergravity

NASA Astrophysics Data System (ADS)

Apruzzi, Fabio; Fazzi, Marco; Passias, Achilleas; Rosa, Dario; Tomasiello, Alessandro

2014-11-01

Very few AdS6 × M 4 supersymmetric solutions are known: one in massive IIA, and two IIB solutions dual to it. The IIA solution is known to be unique; in this paper, we use the pure spinor approach to give a classification for IIB supergravity. We reduce the problem to two PDEs on a two-dimensional space Σ. M 4 is then a fibration of S 2 over Σ; the metric and fluxes are completely determined in terms of the solution to the PDEs. The results seem likely to accommodate near-horizon limits of ( p, q)-fivebrane webs studied in the literature as a source of CFT5's. We also show that there are no AdS6 solutions in eleven-dimensional supergravity.

Exceptional Form of D=11 Supergravity

NASA Astrophysics Data System (ADS)

Hohm, Olaf; Samtleben, Henning

2013-12-01

Eleven-dimensional supergravity reveals large exceptional symmetries upon reduction, in accordance with the U-duality groups of M theory, but their higher-dimensional geometric origin has remained a mystery. In this Letter, we show that D=11 supergravity can be extended to be fully covariant under the exceptional groups En(n), n=6, 7, 8. Motivated by a similar formulation of double field theory we introduce an extended “exceptional spacetime.” We illustrate the construction by giving the explicit E6(6) covariant form: the full D=11 supergravity, in a 5+6 splitting of coordinates but without truncation, embeds into an E6(6) covariant 5+27 dimensional theory. We argue that this covariant form likewise comprises type IIB supergravity.

Stability analysis of compactifications of D = 11 supergravity with SU(3) × SU(2) × U(1) symmetry

NASA Astrophysics Data System (ADS)

Page, Don N.; Pope, C. N.

1984-09-01

We show that the Mpqr Freund-Rubin compactification of eleven-dimensional supergravity is classically stable if and only if 7/2761/2 < -p/q- < 17/117(66)1/2. Permanent address: Blackett Laboratory, Imperial College, London SW7 2BZ, United Kingdom.

A string realisation of Ω-deformed Abelian N =2* theory

NASA Astrophysics Data System (ADS)

Angelantonj, Carlo; Antoniadis, Ignatios; Samsonyan, Marine

2017-10-01

The N =2* supersymmetric gauge theory is a massive deformation of N = 4, in which the adjoint hypermultiplet gets a mass. We present a D-brane realisation of the (non-)Abelian N =2* theory, and compute suitable topological amplitudes, which are expressed as a double series expansion. The coefficients determine couplings of higher-dimensional operators in the effective supergravity action that involve powers of the anti-self-dual N = 2 chiral Weyl superfield and of self-dual gauge field strengths superpartners of the D5-brane coupling modulus. In the field theory limit, the result reproduces the Nekrasov partition function in the two-parameter Ω-background, in agreement with a recent proposal.

Pure spinors, function superspaces and supergravity theories in ten and eleven dimensions

NASA Astrophysics Data System (ADS)

Howe, P. S.

1991-12-01

The constraints of d = 10 supergravity coupled to super Yang-Mills and d = 11 supergravity are studied from the viewpoint of the differential geometry of certain function superspaces. For d = 10 the appropriate function space is loop superspace, and the presence of Chern-Simons terms in the coupling of supergravity to Yang-Mills is incorporated into the formalism via a central extension of the loop group of the Yang-Mills group. For d = 11 the function superspace is the space of maps from a compact two-manifold to superspace. In both cases the superspaces include additional commuting coordinates which are pure spinors. Permanent address: Department of Mathematics, King's College, London WC2R 2LS, UK.

Fayet-Iliopoulos terms in supergravity without gauged R-symmetry

NASA Astrophysics Data System (ADS)

Cribiori, Niccolò; Farakos, Fotis; Tournoy, Magnus; Van Proeyen, Antoine

2018-04-01

We construct a supergravity-Maxwell theory with a novel embedding of the Fayet-Iliopoulos D-term, leading to spontaneous supersymmetry breaking. The gauging of the R-symmetry is not required and a gravitino mass is allowed for a generic vacuum. When matter couplings are introduced, an uplift through a positive definite contribution to the scalar potential is obtained. We observe a notable similarity to the \\overline{D}3 uplift constructions and we give a natural description in terms of constrained multiplets.

RG flows and instantons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gava, Edi

2012-09-24

In these two lectures I discuss RG flow solutions in (1,0) six dimensional supergravity involving SU(2) Yang-Mills instantons. in the conformally flat part of the 6D metric. The solutions interpolate between two (4,0) supersymmetric AdS{sub 3} Multiplication-Sign S{sup 3} backgrounds with different values of AdS{sub 3} and S{sup 3} radii and describe RG flows in the dual 2D SCFT. The flows described are of v.e.v. type, driven by a vacuum expectation value of a (not exactly) marginal operator of dimension 2 in the UV. We give an interpretation of the supergravity solution in terms of the D1/D5 system in typemore » I string theory on K3, whose effective field theory is expected to flow to a (4,0) SCFT in the infrared.« less

Momentum fractionation on superstrata

DOE PAGES

Bena, Iosif; Martinec, Emil; Turton, David; ...

2016-05-11

Superstrata are bound states in string theory that carry D1, D5, and momentum charges, and whose supergravity descriptions are parameterized by arbitrary functions of (at least) two variables. In the D1-D5 CFT, typical three-charge states reside in highdegree twisted sectors, and their momentum charge is carried by modes that individually have fractional momentum. Understanding this momentum fractionation holographically is crucial for understanding typical black-hole microstates in this system. We use solution-generating techniques to add momentum to a multi-wound supertube and thereby construct the first examples of asymptotically-flat superstrata. The resulting supergravity solutions are horizonless and smooth up to well-understood orbifoldmore » singularities. Upon taking the AdS3 decoupling limit, our solutions are dual to CFT states with momentum fractionation. We give a precise proposal for these dual CFT states. Lastly, our construction establishes the very nontrivial fact that large classes of CFT states with momentum fractionation can be realized in the bulk as smooth horizonless supergravity solutions.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amariti, Antonio; Toldo, Chiara

We consider 4d N = 1 SCFTs, topologically twisted on compact constant curvature Riemann surfaces, giving rise to 2d N = (0; 2) SCFTs. The exact R-current of these 2d SCFT extremizes the central charge c 2d, similarly to the 4d picture, where the exact R-current maximizes the central charge a 4d. There are global currents that do not mix with the R-current in 4d but their mixing becomes non trivial in 2d. In this paper we study the holographic dual of this process by analyzing a 5d N = 2 truncation of T 1,1 with one Betti vector multiplet,more » dual to the baryonic current on the CFT side. The holographic realization of the flow across dimensions connects AdS 5 to AdS 3 vacua in the supergravity picture. We verify the existence of the flow to AdS 3 solutions and we retrieve the field theory results for the mixing of the Betti vector with the graviphoton. Moreover, we extract the central charge from the Brown-Henneaux formula, matching with the results obtained in field theory. We develop a general formalism to obtain the central charge of a 2d SCFT from 5d N = 2 gauged supergravity with a generic number of vector multiplets, showing that its extremization corresponds to an attractor mechanism for the scalars in the supergravity picture.« less

Betti multiplets, flows across dimensions and c-extremization

DOE PAGES

Amariti, Antonio; Toldo, Chiara

2017-07-10

We consider 4d N = 1 SCFTs, topologically twisted on compact constant curvature Riemann surfaces, giving rise to 2d N = (0; 2) SCFTs. The exact R-current of these 2d SCFT extremizes the central charge c 2d, similarly to the 4d picture, where the exact R-current maximizes the central charge a 4d. There are global currents that do not mix with the R-current in 4d but their mixing becomes non trivial in 2d. In this paper we study the holographic dual of this process by analyzing a 5d N = 2 truncation of T 1,1 with one Betti vector multiplet,more » dual to the baryonic current on the CFT side. The holographic realization of the flow across dimensions connects AdS 5 to AdS 3 vacua in the supergravity picture. We verify the existence of the flow to AdS 3 solutions and we retrieve the field theory results for the mixing of the Betti vector with the graviphoton. Moreover, we extract the central charge from the Brown-Henneaux formula, matching with the results obtained in field theory. We develop a general formalism to obtain the central charge of a 2d SCFT from 5d N = 2 gauged supergravity with a generic number of vector multiplets, showing that its extremization corresponds to an attractor mechanism for the scalars in the supergravity picture.« less

Betti multiplets, flows across dimensions and c-extremization

NASA Astrophysics Data System (ADS)

Amariti, Antonio; Toldo, Chiara

2017-07-01

We consider 4d N = 1 SCFTs, topologically twisted on compact constant curvature Riemann surfaces, giving rise to 2d N = (0, 2) SCFTs. The exact R-current of these 2d SCFT extremizes the central charge c 2 d , similarly to the 4d picture, where the exact R-current maximizes the central charge a 4 d . There are global currents that do not mix with the R-current in 4d but their mixing becomes non trivial in 2d. In this paper we study the holographic dual of this process by analyzing a 5d N = 2 truncation of T 1,1 with one Betti vector multiplet, dual to the baryonic current on the CFT side. The holographic realization of the flow across dimensions connects AdS5 to AdS3 vacua in the supergravity picture. We verify the existence of the flow to AdS3 solutions and we retrieve the field theory results for the mixing of the Betti vector with the graviphoton. Moreover, we extract the central charge from the Brown-Henneaux formula, matching with the results obtained in field theory. We develop a general formalism to obtain the central charge of a 2d SCFT from 5d N = 2 gauged supergravity with a generic number of vector multiplets, showing that its extremization corresponds to an attractor mechanism for the scalars in the supergravity picture.

Equivalent D = 3 supergravity amplitudes from double copies of three-algebra and two-algebra gauge theories.

PubMed

Huang, Yu-tin; Johansson, Henrik

2013-04-26

We show that three-dimensional supergravity amplitudes can be obtained as double copies of either three-algebra super-Chern-Simons matter theory or two-algebra super-Yang-Mills theory when either theory is organized to display the color-kinematics duality. We prove that only helicity-conserving four-dimensional gravity amplitudes have nonvanishing descendants when reduced to three dimensions, implying the vanishing of odd-multiplicity S-matrix elements, in agreement with Chern-Simons matter theory. We explicitly verify the double-copy correspondence at four and six points for N = 12,10,8 supergravity theories and discuss its validity for all multiplicity.

Non-BPS attractors in 5 d and 6 d extended supergravity

NASA Astrophysics Data System (ADS)

Andrianopoli, L.; Ferrara, S.; Marrani, A.; Trigiante, M.

2008-05-01

We connect the attractor equations of a certain class of N=2, d=5 supergravities with their (1,0), d=6 counterparts, by relating the moduli space of non-BPS d=5 black hole/black string attractors to the moduli space of extremal dyonic black string d=6 non-BPS attractors. For d=5 real special symmetric spaces and for N=4,6,8 theories, we explicitly compute the flat directions of the black object potential corresponding to vanishing eigenvalues of its Hessian matrix. In the case N=4, we study the relation to the (2,0), d=6 theory. We finally describe the embedding of the N=2, d=5 magic models in N=8, d=5 supergravity as well as the interconnection among the corresponding charge orbits.

General nonextremal rotating charged Gödel black holes in minimal five-dimensional gauged supergravity.

PubMed

Wu, Shuang-Qing

2008-03-28

I present the general exact solutions for nonextremal rotating charged black holes in the Gödel universe of five-dimensional minimal supergravity theory. They are uniquely characterized by four nontrivial parameters: namely, the mass m, the charge q, the Kerr equal rotation parameter a, and the Gödel parameter j. I calculate the conserved energy, angular momenta, and charge for the solutions and show that they completely satisfy the first law of black hole thermodynamics. I also study the symmetry and separability of the Hamilton-Jacobi and the massive Klein-Gordon equations in these Einstein-Maxwell-Chern-Simons-Gödel black hole backgrounds.

Integral group actions on symmetric spaces and discrete duality symmetries of supergravity theories

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carbone, Lisa; Murray, Scott H.; Sati, Hisham

For G = G(ℝ), a split, simply connected, semisimple Lie group of rank n and K the maximal compact subgroup of G, we give a method for computing Iwasawa coordinates of K∖G using the Chevalley generators and the Steinberg presentation. When K∖G is a scalar coset for a supergravity theory in dimensions ≥3, we determine the action of the integral form G(ℤ) on K∖G. We give explicit results for the action of the discrete U-duality groups SL{sub 2}(ℤ) and E{sub 7}(ℤ) on the scalar cosets SO(2)∖SL{sub 2}(ℝ) and [SU(8)/( ± Id)]∖E{sub 7(+7)}(ℝ) for type IIB supergravity in ten dimensions andmore » 11-dimensional supergravity reduced to D = 4 dimensions, respectively. For the former, we use this to determine the discrete U-duality transformations on the scalar sector in the Borel gauge and we describe the discrete symmetries of the dyonic charge lattice. We determine the spectrum-generating symmetry group for fundamental BPS solitons of type IIB supergravity in D = 10 dimensions at the classical level and we propose an analog of this symmetry at the quantum level. We indicate how our methods can be used to study the orbits of discrete U-duality groups in general.« less

Computing the scalar field couplings in 6D supergravity

NASA Astrophysics Data System (ADS)

Saidi, El Hassan

2008-11-01

Using non-chiral supersymmetry in 6D space-time, we compute the explicit expression of the metric the scalar manifold SO(1,1)×{SO(4,20)}/{SO(4)×SO(20)} of the ten-dimensional type IIA superstring on generic K3. We consider as well the scalar field self-couplings in the general case where the non-chiral 6D supergravity multiplet is coupled to generic n vector supermultiplets with moduli space SO(1,1)×{SO(4,n)}/{SO(4)×SO(n)}. We also work out a dictionary giving a correspondence between hyper-Kähler geometry and the Kähler geometry of the Coulomb branch of 10D type IIA on Calabi-Yau threefolds. Others features are also discussed.

Spinorial Geometry and Supergravity

NASA Astrophysics Data System (ADS)

Gillard, Joe

2006-08-01

In the main part of this thesis, we present the foundations and initial results of the Spinorial Geometry formalism for solving Killing spinor equations. This method can be used for any supergravity theory, although we largely focus on D=11 supergravity. The D=5 case is investigated in an appendix. The exposition provides a comprehensive introduction to the formalism, and contains background material on the complex spin representations which, it is hoped, will provide a useful bridge between the mathematical literature and our methods. Many solutions to the D=11 Killing spinor equations are presented, and the consequences for the spacetime geometry are explored in each case. Also in this thesis, we consider another class of supergravity solutions, namely heterotic string backgrounds with (2,0) world-sheet supersymmetry. We investigate the consequences of taking alpha-prime corrections into account in the field equations, in order to remain consistent with anomaly cancellation, while requiring that spacetime supersymmetry is preserved.

Supergravity, dark energy, and the fate of the universe

NASA Astrophysics Data System (ADS)

Kallosh, Renata; Linde, Andrei; Prokushkin, Sergey; Shmakova, Marina

2002-12-01

We propose a description of dark energy and acceleration of the universe in extended supergravities with de Sitter (dS) solutions. Some of them are related to M theory with noncompact internal spaces. Masses of ultralight scalars in these models are quantized in units of the Hubble constant: m2=nH2. If the dS solution corresponds to a minimum of the effective potential, the universe eventually becomes dS space. If the dS solution corresponds to a maximum or a saddle point, which is the case in all known models based on N=8 supergravity, the flat universe eventually stops accelerating and collapses to a singularity. We show that in these models, as well as in the simplest models of dark energy based on N=1 supergravity, the typical time remaining before the global collapse is comparable to the present age of the universe, t=O(1010) yr. We discuss the possibility of distinguishing between various models and finding our destiny using cosmological observations.

Quantum Structure of Space and Time

NASA Astrophysics Data System (ADS)

Duff, M. J.; Isham, C. J.

2012-07-01

Foreword Abdus Salam; Preface; List of participants; Part I. Quantum Gravity, Fields and Topology: 1. Some remarks on gravity and quantum mechanics Roger Penrose; 2. An experimental test of quantum gravity Don N. Page and C. D. Geilker; 3. Quantum mechanical origin of the sandwich theorem in classical gravitation theory Claudio Teitelboim; 4. θ-States induced by the diffeomorphism group in canonically quantized gravity C. J. Isham; 5. Strong coupling quantum gravity: an introduction Martin Pilati; 6. Quantizing fourth order gravity theories S. M. Christensen; 7. Green's functions, states and renormalisation M. R. Brown and A. C. Ottewill; 8. Introduction to quantum regge calculus Martin Roček and Ruth Williams; 9. Spontaneous symmetry breaking in curved space-time D. J. Toms; 10. Spontaneous symmetry breaking near a black hole M. S. Fawcett and B. F. Whiting; 11. Yang-Mills vacua in a general three-space G. Kunstatter; 12. Fermion fractionization in physics R. Jackiw; Part II. Supergravity: 13. The new minimal formulation of N=1 supergravity and its tensor calculus M. F. Sohnius and P. C. West; 14. A new deteriorated energy-momentum tensor M. J. Duff and P. K. Townsend; 15. Off-shell N=2 and N=4 supergravity in five dimensions P. Howe; 16. Supergravity in high dimensions P. van Niewenhuizen; 17. Building linearised extended supergravities J. G. Taylor; 18. (Super)gravity in the complex angular momentum plane M. T. Grisaru; 19. The multiplet structure of solitons in the O(2) supergravity theory G. W. Gibbons; 20. Ultra-violet properties of supersymmetric gauge theory S. Ferrara; 21. Extended supercurrents and the ultra-violet finiteness of N=4 supersymmetric Yang-Mills theories K. S. Stelle; 22. Duality rotations B. Zumino; Part III. Cosmology and the Early Universe: 23. Energy, stability and cosmological constant S. Deser; 24. Phase transitions in the early universe T. W. B. Kibble; 25. Complete cosmological theories L. P. Grishchuk and Ya. B. Zeldovich; 26. The cosmological constant and the weak anthropic principle S. W. Hawking.

Heterotic supergravity with internal almost-Kähler spaces; instantons for SO(32), or E 8 × E 8, gauge groups; and deformed black holes with soliton, quasiperiodic and/or pattern-forming structures

NASA Astrophysics Data System (ADS)

Bubuianu, Laurenţiu; Irwin, Klee; Vacaru, Sergiu I.

2017-04-01

Heterotic supergravity with (1  +  3)-dimensional domain wall configurations and (warped) internal, six dimensional, almost-Kähler manifolds {{}6}\\text{X} are studied. Considering ten dimensional spacetimes with nonholonomic distributions and conventional double fibrations, 2  +  2  +  ...  =  2  +  2  +  3  +  3, and associated SU(3) structures on internal space, we generalize for real, internal, almost symplectic gravitational structures the constructions with gravitational and gauge instantons of tanh-kink type [1, 2]. They include the first {α\\prime} corrections to the heterotic supergravity action, parameterized in a form to imply nonholonomic deformations of the Yang-Mills sector and corresponding Bianchi identities. We show how it is possible to construct a variety of solutions depending on the type of nonholonomic distributions and deformations of ‘prime’ instanton configurations characterized by two real supercharges. This corresponds to N=1/2 supersymmetric, nonholonomic manifolds from the four dimensional point of view. Our method provides a unified description of embedding nonholonomically deformed tanh-kink-type instantons into half-BPS solutions of heterotic supergravity. This allows us to elaborate new geometric methods of constructing exact solutions of motion equations, with first order {α\\prime} corrections to the heterotic supergravity. Such a formalism is applied for general and/or warped almost-Kähler configurations, which allows us to generate nontrivial (1  +  3)-d domain walls and black hole deformations determined by quasiperiodic internal space structures. This formalism is utilized in our associated publication [3] in order to construct and study generic off-diagonal nonholonomic deformations of the Kerr metric, encoding contributions from heterotic supergravity.

The topological structure of supergravity: an application to supersymmetric localization

NASA Astrophysics Data System (ADS)

Imbimbo, Camillo; Rosa, Dario

2018-05-01

The BRST algebra of supergravity is characterized by two different bilinears of the commuting supersymmetry ghosts: a vector γ μ and a scalar ϕ, the latter valued in the Yang-Mills Lie algebra. We observe that under BRST transformations γ and ϕ transform as the superghosts of, respectively, topological gravity and topological Yang-Mills coupled to topological gravity. This topological structure sitting inside any supergravity leads to universal equivariant cohomological equations for the curvatures 2-forms which hold on supersymmetric bosonic backgrounds. Additional equivariant cohomological equations can be derived for supersymmetric backgrounds of supergravities for which certain gauge invariant scalar bilinears of the commuting ghosts exist. Among those, N = (2 , 2) in d = 2, which we discuss in detail in this paper, and N = 2 in d = 4.

Fluxes, holography and twistors: String theory paths to four dimensions

NASA Astrophysics Data System (ADS)

Gao, Peng

2007-12-01

There are presently three popular paths to obtain four dimensional physics from string theory: compactification, holography and twistor space. We present results in this thesis on each of them, discussing the geometric structure of flux compactifications, the interplay between holography and S -duality in M-theory and the perturbative amplitudes of the marginally deformed super-Yang-Mills theory obtained from topological string theory on a supertwistor space. First we analyze supersymmetric flux compactifications of ten dimensional string theories to four dimensions. Back reaction of the fluxes on the six dimensional internal geometry is characterized by G-structures. In type IIB compactification on SU(3)-structure manifold with N = 1 supersymmetry, we solve the equations dictating the five components of intrinsic torsion. We find that the six dimensional manifold always retains an integrable almost complex structure compatible with supersymmetry. In terms of the various vacuum fields, the axion/dilaton is found to be generically non-holomorphic, and the four dimensional cosmological constant is nonvanishing only if the SU(3) structure group is reduced to SU(2). The equations are solved by one holomorphic function. Around the poles and zeros of the holomorphic function, the geometry locally looks like the well known type-A and type-B solutions. When this function is a constant, the geometry can be viewed as a holographic RG flow. After classifying the type IIB SU(3)-structure flux vacua, we analyze the effect of non-perturbative corrections on the moduli space of N = 2 flux compactifications. At energy below the Kaluza-Klein scale, the four dimensional effective theory is a gauged supergravity theory with vanishing cosmological constant. The gauging of isometries on the hyper-multiplet moduli space is induced by the fluxes. We show that instanton corrections which could potentially lift the gauged isometries are in fact prohibited both in the type IIA and heterotic string theories by the inclusion of flux. Hence gauged supergravity is a robust framework for studying flux vacua even when these stringy effects are taken into account. The mechanisms which protect the gauged isometries are different in the two theories. Then we switch to the understanding of SL(2, Z ) duality transformations in asymptotically AdS4 x S7 spacetime with an Abelian gauge theory. The bulk duality acts non-trivially on the three-dimensional SCFT of coincident M2-branes on the conformal boundary. We develop a systematic method to holographically obtain the deformations of the boundary CFT manifested by generalized boundary conditions and show how SL(2, Z ) duality relates different deformations of the conformal vacuum. We analyze in detail marginal deformations and deformations by dimension 4 operators. In the case of massive deformations, the RG flow induces a Legendre transform as well as S-duality. Correlation functions in the CFT are computed by differentiating with respect to magnetic bulk sources, whereas correlation functions in the Legendre dual CFT are computed using electric bulk sources. Under massive deformations, the boundary effective action is generically minimized by massive self-dual configurations of the U(1) gauge field. We show that a massive and self-dual boundary condition corresponds to the unique self-dual topologically massive gauge theory in three dimensions. Thus, self-duality in three dimensions can be understood as a consequence of SL(2, Z ) invariance in the bulk of AdS4. We discuss various implications for understanding the strongly interacting worldvolume theory of M2-branes and more general dualities of the maximally supersymmetric AdS4 supergravity theory. Finally we study the twistor string theory whose D-instanton expansion gives the perturbative expansion of marginally deformed N = 4 super-Yang-Mills theories. More precisely this string theory is a topological B-model with both open and closed string sectors with target space CP3|4 , a super-Calabi-Yau manifold. The tree-level amplitudes in the N = 1 beta-deformed field theory are exactly reproduced by introducing non-anticommutative star-products among the D1 and D5 open strings. A related star-product gives the tree-level amplitudes of the non-supersymmetric gamma-deformed conformal field theory. The non-anticommutativity arises essentially from the deformation of the supertwistor space which reduces the amount of superconformal symmetries realized by the supertwistor space. The tree-level gluonic amplitudes in more general marginally deformed field theories are also discussed using twistor string theory.

On the fakeness of fake supergravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Celi, Alessio; Proeyen, Antoine van; Ceresole, Anna

2005-02-15

We revisit and complete the study of curved BPS-domain walls in matter-coupled 5D, N=2 supergravity and carefully analyze the relation to gravitational theories known as ''fake supergravities.'' We first show that curved BPS-domain walls require the presence of nontrivial hypermultiplet scalars, whereas walls that are solely supported by vector multiplet scalars are necessarily flat, due to the constraints from very special geometry. We then recover fake supergravity as the effective description of true supergravity where one restricts the attention to the flowing scalar field of a given BPS-domain wall. In general, however, true supergravity can be simulated by fake supergravitymore » at most locally, based upon two choices: (i) a suitable adapted coordinate system on the scalar manifold, such that only one scalar field plays a dynamical role, and (ii) a gauge fixing of the SU(2) connection on the quaternionic-Kaehler manifold, as this connection does not fit the simple formalism of fake supergravity. Employing these gauge and coordinate choices, the BPS-equations for both vector and hypermultiplet scalars become identical to the fake supergravity equations, once the line of flow is determined by the full supergravity equations.« less

ANOMALY STRUCTURE OF SUPERGRAVITY AND ANOMALY CANCELLATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Butter, Daniel; Gaillard, Mary K.

2009-06-10

We display the full anomaly structure of supergravity, including new D-term contributions to the conformal anomaly. This expression has the super-Weyl and chiral U(1){sub K} transformation properties that are required for implementation of the Green-Schwarz mechanism for anomaly cancellation. We outline the procedure for full anomaly cancellation. Our results have implications for effective supergravity theories from the weakly coupled heterotic string theory.

Noncommutative massive unquenched ABJM

NASA Astrophysics Data System (ADS)

Bea, Yago; Jokela, Niko; Pönni, Arttu; Ramallo, Alfonso V.

2018-05-01

In this paper, we study noncommutative massive unquenched Chern-Simons matter theory using its gravity dual. We construct this novel background by applying a TsT-transformation on the known parent commutative solution. We discuss several aspects of this solution to the Type IIA supergravity equations of motion and, amongst others, check that it preserves 𝒩 = 1 supersymmetry. We then turn our attention to applications and investigate how dynamical flavor degrees of freedom affect numerous observables of interest. Our framework can be regarded as a key step toward the construction of holographic quantum Hall states on a noncommutative plane.

Supersymmetry, Supergravity, and Unification

NASA Astrophysics Data System (ADS)

Nath, Pran

2016-12-01

Dedication; Preface; 1. A brief history of unification; 2. Gravitation; 3. Non-abelian gauge theory; 4. Spontaneous breaking of global and local symmetries; 5. The Standard Model; 6. Anomalies; 7. Effective Lagrangians; 8. Supersymmetry; 9. Grand unification; 10. MSSM Lagrangian; 11. N = 1 supergravity; 12. Coupling of supergravity with matter and gauge fields; 13. Supergravity grand unification; 14. Phenomenology of supergravity grand unification; 15. CP violation in supergravity unified theories; 16. Proton stability in supergravity unified theories; 17. Cosmology, astroparticle physics and SUGRA unification; 18. Extended supergravities and supergravities from superstrings; 19. Specialized topics; 20. The future of unification; 21. Appendices; 22. Notations, conventions, and formulae; 23. Physical constants; 24. List of books and reviews for further reading; Index.

Dimensionality in Supergravity Cosmology

NASA Astrophysics Data System (ADS)

Wu, Zhong Chao

2008-01-01

It is shown that in d = 11 supergravity, under a very reasonable ansatz, the observable spacetime must be 4-dimensional. The spacetime dimensionality, for the first time, is proven from the First Principle, instead of the Anthropic Principle.

BPS objects in D = 7 supergravity and their M-theory origin

NASA Astrophysics Data System (ADS)

Dibitetto, Giuseppe; Petri, Nicolò

2017-12-01

We study several different types of BPS flows within minimal N=1 , D = 7 supergravity with SU(2) gauge group and non-vanishing topological mass. After reviewing some known domain wall solutions involving only the metric and the ℝ+ scalar field, we move to considering more general flows involving a "dyonic" profile for the 3-form gauge potential. In this context, we consider flows featuring a Mkw3 as well as an AdS3 slicing, write down the corresponding flow equations, and integrate them analytically to obtain many examples of asymptotically AdS7 solutions in presence of a running 3-form. Furthermore, we move to adding the possibility of non-vanishing vector fields, find the new corresponding flows and integrate them numerically. Finally, we discuss the eleven-dimensional interpretation of the aforementioned solutions as effective descriptions of M2 - M5 bound states.

Supersymmetric solutions of the cosmological, gauged, ℂ magic model

NASA Astrophysics Data System (ADS)

Chimento, Samuele; Ortín, Tomás; Ruipérez, Alejandro

2018-05-01

We construct supersymmetric solutions of theories of gauged N = 1 , d = 5 supergravity coupled to vector multiplets with a U(1)R Abelian (Fayet-Iliopoulos) gauging and an independent SU(2) gauging associated to an SU(2) isometry group of the Real Special scalar manifold. These theories provide minimal supersymmetrizations of 5-dimensional SU(2) Einstein-Yang-Mills theories with negative cosmological constant. We consider a minimal model with these gauge groups and the "magic model" based on the Jordan algebra J 3 ℂ with gauge group SU(3) × U(1)R, which is a consistent truncation of maximal SO(6)-gauged supergravity in d = 5 and whose solutions can be embedded in Type IIB Superstring Theory. We find several solutions containing selfdual SU(2) instantons, some of which asymptote to AdS5 and some of which are very small, supersymmetric, deformations of AdS5. We also show how some of those solutions can be embedded in Romans' SU(2) × U(1)-gauged half-maximal supergravity, which was obtained by Lu, Pope and Tran by compactification of the Type IIB Superstring effective action. This provides another way of uplifting those solutions to 10 dimensions.

Infinite tension limit of the pure spinor superstring

NASA Astrophysics Data System (ADS)

Berkovits, Nathan

2014-03-01

Mason and Skinner recently constructed a chiral infinite tension limit of the Ramond-Neveu-Schwarz superstring which was shown to compute the Cachazo-He-Yuan formulae for tree-level d = 10 Yang-Mills amplitudes and the NS-NS sector of tree-level d = 10 supergravity amplitudes. In this letter, their chiral infinite tension limit is generalized to the pure spinor superstring which computes a d = 10 superspace version of the Cachazo-He-Yuan formulae for tree-level d = 10 super-Yang-Mills and supergravity amplitudes.

M-theory superstrata and the MSW string

DOE PAGES

Bena, Iosif; Martinec, Emil; Turton, David; ...

2017-06-26

The low-energy description of wrapped M5 branes in compactifications of M-theory on a Calabi-Yau threefold times a circle is given by a conformal field theory studied by Maldacena, Strominger and Witten and known as the MSW CFT. Taking the threefold to be T 6 or K3×T 2, we construct a map between a sub-sector of this CFT and a sub-sector of the D1-D5 CFT. We demonstrate this map by considering a set of D1-D5 CFT states that have smooth horizonless bulk duals, and explicitly constructing the supergravity solutions dual to the corresponding states of the MSW CFT. We thus obtainmore » the largest known class of solutions dual to MSW CFT microstates, and demonstrate that five-dimensional ungauged supergravity admits much larger families of smooth horizonless solutions than previously known.« less

On curvature squared invariants in 6D supergravity

NASA Astrophysics Data System (ADS)

Novak, J.; Tartaglino-Mazzucchelli, G.

2018-02-01

We review recent developments in the construction of curvature squared invariants in off-shell \\mathscr{N} = (1, 0) supergravity in six dimensions. Based on the talk presented by GT-M at ISQS25 (Prague, Czech Republic, 6 { 10 June, 2017).

Chaotic inflation in Jordan frame supergravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Hyun Min, E-mail: hyun.min.lee@cern.ch

2010-08-01

We consider the inflationary scenario with non-minimal coupling in 4D Jordan frame supergravity. We find that there occurs a tachyonic instability along the direction of the accompanying non-inflaton field in generic Jordan frame supergravity models. We propose a higher order correction to the Jordan frame function for solving the tachyonic mass problem and show that the necessary correction can be naturally generated by the heavy thresholds without spoiling the slow-roll conditions. We discuss the implication of the result on the Higgs inflation in NMSSM.

Fibre inflation and α-attractors

NASA Astrophysics Data System (ADS)

Kallosh, Renata; Linde, Andrei; Roest, Diederik; Westphal, Alexander; Yamada, Yusuke

2018-02-01

Fibre inflation is a specific string theory construction based on the Large Volume Scenario that produces an inflationary plateau. We outline its relation to α-attractor models for inflation, with the cosmological sector originating from certain string theory corrections leading to α = 2 and α = 1/2. Above a certain field range, the steepening effect of higher-order corrections leads first to the breakdown of single-field slow-roll and after that to the onset of 2-field dynamics: the overall volume of the extra dimensions starts to participate in the effective dynamics. Finally, we propose effective supergravity models of fibre inflation based on an \\overline{D3} uplift term with a nilpotent superfield. Specific moduli dependent \\overline{D3} induced geometries lead to cosmological fibre models but have in addition a de Sitter minimum exit. These supergravity models motivated by fibre inflation are relatively simple, stabilize the axions and disentangle the Hubble parameter from supersymmetry breaking.

Gauge supergravity in D = 2 + 2

NASA Astrophysics Data System (ADS)

Castellani, Leonardo

2017-10-01

We present an action for chiral N = (1 , 0) supergravity in 2 + 2 dimensions. The fields of the theory are organized into an OSp(1|4) connection supermatrix, and are given by the usual vierbein V a , spin connection ω ab , and Majorana gravitino ψ. In analogy with a construction used for D = 10 + 2 gauge supergravity, the action is given by ∫STr( R 2 Γ), where R is the OSp(1|4) curvature supermatrix two-form, and Γ a constant supermatrix containing γ 5. It is similar, but not identical to the MacDowell-Mansouri action for D = 2 + 2 supergravity. The constant supermatrix breaks OSp(1|4) gauge invariance to a subalgebra OSp(1|2) ⊕ Sp(2), including a Majorana-Weyl supercharge. Thus half of the OSp(1|4) gauge supersymmetry survives. The gauge fields are the selfdual part of ω ab and the Weyl projection of ψ for OSp(1|2), and the antiselfdual part of ω ab for Sp(2). Supersymmetry transformations, being part of a gauge superalgebra, close off-shell. The selfduality condition on the spin connection can be consistently imposed, and the resulting "projected" action is OSp(1|2) gauge invariant.

On the dualization of scalars into ( d - 2)-forms in supergravity. Momentum maps, R-symmetry and gauged supergravity

NASA Astrophysics Data System (ADS)

Bandos, Igor A.; Ortín, Tomás

2016-08-01

We review and investigate different aspects of scalar fields in supergravity theories both when they parametrize symmetric spaces and when they parametrize spaces of special holonomy which are not necessarily symmetric (Kähler and Quaternionic-Kähler spaces): their rôle in the definition of derivatives of the fermions covariant under the R-symmetry group and (in gauged supergravities) under some gauge group, their dualization into ( d - 2)-forms, their role in the supersymmetry transformation rules (via fermion shifts, for instance) etc. We find a general definition of momentum map that applies to any manifold admitting a Killing vector and coincides with those of the holomorphic and tri-holomorphic momentum maps in Kähler and quaternionic-Kähler spaces and with an independent definition that can be given in symmetric spaces. We show how the momen-tum map occurs ubiquitously: in gauge-covariant derivatives of fermions, in fermion shifts, in the supersymmetry transformation rules of ( d - 2)-forms etc. We also give the general structure of the Noether-Gaillard-Zumino conserved currents in theories with fields of different ranks in any dimension.

Inner space/outer space - The interface between cosmology and particle physics

NASA Astrophysics Data System (ADS)

Kolb, Edward W.; Turner, Michael S.; Lindley, David; Olive, Keith; Seckel, David

A collection of papers covering the synthesis between particle physics and cosmology is presented. The general topics addressed include: standard models of particle physics and cosmology; microwave background radiation; origin and evolution of large-scale structure; inflation; massive magnetic monopoles; supersymmetry, supergravity, and quantum gravity; cosmological constraints on particle physics; Kaluza-Klein cosmology; and future directions and connections in particle physics and cosmology.

Superbranes, D = 11 CJS Supergravity and Enlarged Superspace Coordinates/Fields Correspondence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Azcarraga, J.A. de; IFIC - CSIC-UVEG, Facultad de Fisica, 46100-Burjassot, Valencia

2005-04-25

We discuss the role of enlarged superspaces in two seemingly different contexts, the structure of the p-brane actions and that of the Cremmer-Julia-Scherk eleven-dimensional supergravity. Both provide examples of a common principle: the existence of an enlarged superspaces coordinates/fields correspondence by which all the (worldvolume or spacetime) fields of the theory are associated to coordinates of enlarged superspaces. In the context of p-branes, enlarged superspaces may be used to construct manifestly supersymmetry-invariant Wess-Zumino terms and as a way of expressing the Born-Infeld worldvolume fields of D-branes and the worldvolume M5-brane two-form in terms of fields associated to the coordinates ofmore » these enlarged superspaces. This is tantamount to saying that the Born-Infeld fields have a superspace origin, as do the other worldvolume fields, and that they have a composite structure. In D=11 supergravity theory enlarged superspaces arise when its underlying gauge structure is investigated and, as a result, the composite nature of the A3 field is revealed: there is a full one-parametric family of enlarged superspace groups that solve the problem of expressing A3 in terms of spacetime fields associated to their coordinates. The corresponding enlarged supersymmetry algebras turn out to be deformations of an expansion of the osp(1 vertical bar 32) algebra. The unifying mathematical structure underlying all these facts is the cohomology of the supersymmetry algebras involved.« less

Physics of superheavy dark matter in supergravity

NASA Astrophysics Data System (ADS)

Addazi, Andrea; Marciano, Antonino; Ketov, Sergei V.; Khlopov, Maxim Yu.

New trends in inflationary model building and dark matter production in supergravity are considered. Starobinsky inflation is embedded into 𝒩 = 1 supergravity, avoiding instability problems, when the inflaton belongs to a vector superfield associated with a U(1) gauge symmetry, instead of a chiral superfield. This gauge symmetry can be spontaneously broken by the super-Higgs mechanism resulting in a massive vector supermultiplet including the (real scalar) inflaton field. Both supersymmetry (SUSY) and the R-symmetry can also be spontaneously broken by the Polonyi mechanism at high scales close to the inflationary scale. In this case, Polonyi particles and gravitinos become superheavy, and can be copiously produced during inflation by the Schwinger mechanism sourced by the universe expansion. The Polonyi mass slightly exceeds twice the gravitino mass, so that Polonyi particles are unstable and decay into gravitinos. Considering the mechanisms of superheavy gravitino production, we find that the right amount of cold dark matter composed of gravitinos can be achieved. In our scenario, the parameter space of the inflaton potential is directly related to the dark matter one, providing a new unifying framework of inflation and dark matter genesis. A multi-superfield extension of the supergravity framework with a single (inflaton) superfield can result in a formation of primordial nonlinear structures like mini- and stellar-mass black holes, primordial nongaussianity, and the running spectral index of density fluctuations. This framework can be embedded into the SUSY GUTs inspired by heterotic string compactifications on Calabi-Yau three-folds, thus unifying particle physics with quantum gravity.

Trivial solutions of generalized supergravity vs non-abelian T-duality anomaly

NASA Astrophysics Data System (ADS)

Wulff, Linus

2018-06-01

The equations that follow from kappa symmetry of the type II Green-Schwarz string are a certain deformation, by a Killing vector field K, of the type II supergravity equations. We analyze under what conditions solutions of these 'generalized' supergravity equations are trivial in the sense that they solve also the standard supergravity equations. We argue that for this to happen K must be null and satisfy dK =iK H with H = dB the NSNS three-form field strength. Non-trivial examples are provided by symmetric pp-wave solutions. We then analyze the consequences for non-abelian T-duality and the closely related homogenous Yang-Baxter sigma models. When one performs non-abelian T-duality of a string sigma model on a non-unimodular (sub)algebra one generates a non-vanishing K proportional to the trace of the structure constants. This is expected to lead to an anomaly but we show that when K satisfies the same conditions the anomaly in fact goes away leading to more possibilities for non-anomalous non-abelian T-duality.

4D superfield reduction of 5D orbifold SUGRA and heterotic M-theory

NASA Astrophysics Data System (ADS)

Paccetti Correia, Filipe; Schmidt, Michael G.; Tavartkiladze, Zurab

2006-09-01

We present a detailed study of the reduction to 4D of 5D supergravity compactified on the S/Z orbifold. For this purpose we develop and employ a recently proposed N=1 conformal superfield description of the 5D supergravity couplings to Abelian vector and hypermultiplets. In particular, we obtain a unique relation of the "radion" to chiral superfields as in global 5D SUSY and we can embed the universal hypermultiplet into this formalism. In our approach, it is transparent how the superconformal structure of the effective 4D actions is inherited from the one of the original 5D supergravity. We consider both ungauged and gauged 5D supergravities. This includes compactifications in unwarped geometries, generalizations of the supersymmetric Randall-Sundrum (RS) model as well as 5D heterotic M-theory. In the unwarped case, after obtaining the effective Kähler potentials and superpotentials, we demonstrate that the tree-level 4D potentials have flat and/or tachyonic directions. One-loop corrections to the Kähler potential and gaugino condensation are presented as suitable tools for moduli stabilization to be discussed in subsequent work. Turning to the RS-like models, we obtain a master formula for the Kähler potential for an arbitrary number of vector and hyper moduli, which we evaluate exactly for special cases. Finally, we formulate the superfield description of 5D heterotic M-theory and obtain its effective 4D description for the universal ( h=1) case, in the presence of an arbitrary number of bulk 5-branes. We present, as a check of our expressions, time-dependent solutions of 4D heterotic M-theory, which uplift to 5D solutions generalizing the ones recently found in [W. Chen, Z.-W. Chong, G.W. Gibbons, H. Lü, C.N. Pope, Hořava-Witten stability: Eppur si muove, Nucl. Phys. B 732 (2006) 118, hep-th/0502077].

Holographic duals of 3d S-fold CFTs

NASA Astrophysics Data System (ADS)

Assel, Benjamin; Tomasiello, Alessandro

2018-06-01

We construct non-geometric AdS4 solutions of IIB string theory where the fields in overlapping patches are glued by elements of the S-duality group. We obtain them by suitable quotients of compact and non-compact geometric solutions. The quotient procedure suggests CFT duals as quiver theories with links involving the so-called T [U( N)] theory. We test the validity of the non-geometric solutions (and of our proposed holographic duality) by computing the three-sphere partition function Z of the CFTs. A first class of solutions is obtained by an S-duality quotient of Janus-type non-compact solutions and is dual to 3d N=4 SCFTs; for these we manage to compute Z of the dual CFT at finite N, and it agrees perfectly with the supergravity result in the large N limit. A second class has five-branes, it is obtained by a Möbius-like S-quotient of ordinary compact solutions and is dual to 3d N=3 SCFTs. For these, Z agrees with the supergravity result if one chooses the limit carefully so that the effect of the fivebranes does not backreact on the entire geometry. Other limits suggest the existence of IIA duals.

AdS7/CFT6 with orientifolds

NASA Astrophysics Data System (ADS)

Apruzzi, Fabio; Fazzi, Marco

2018-01-01

AdS7 solutions of massive type IIA have been classified, and are dual to a large class of six-dimensional (1, 0) SCFT's whose tensor branch deformations are described by linear quivers of SU groups. Quivers and AdS vacua depend solely on the group theory data of the NS5-D6-D8 brane configurations engineering the field theories. This has allowed for a direct holographic match of their a conformal anomaly. In this paper we extend the match to cases where O6 and O8-planes are present, thereby introducing SO and USp groups in the quivers. In all of them we show that the a anomaly computed in supergravity agrees with the holographic limit of the exact field theory result, which we extract from the anomaly polynomial. As a byproduct we construct special AdS7 vacua dual to nonperturbative F-theory configurations. Finally, we propose a holographic a-theorem for six-dimensional Higgs branch RG flows.

The clockwork supergravity

NASA Astrophysics Data System (ADS)

Kehagias, Alex; Riotto, Antonio

2018-02-01

We show that the minimal D = 5, N = 2 gauged supergravity set-up may encode naturally the recently proposed clockwork mechanism. The minimal embedding requires one vector multiplet in addition to the supergravity multiplet and the clockwork scalar is identified with the scalar in the vector multiplet. The scalar has a two-parameter potential and it can accommodate the clockwork, the Randall-Sundrum and a no-scale model with a flat potential, depending on the values of the parameters. The continuous clockwork background breaks half of the original supersymmetries, leaving a D = 4, N = 1 theory on the boundaries. We also show that the generated hierarchy by the clockwork is not exponential but rather power law. The reason is that four-dimensional Planck scale has a power-law dependence on the compactification radius, whereas the corresponding KK spectrum depends on the logarithm of the latter.

Canonical coordinates and meson spectra for scalar deformed Script N = 4 SYM from the AdS/CFT correspondence

NASA Astrophysics Data System (ADS)

Shock, Jonathan P.

2006-10-01

Two points on the Coulomb branch of Script N = 4 super Yang Mills are investigated using their supergravity duals. By switching on condensates for the scalars in the Script N = 4 multiplet with a form which preserves a subgroup of the original R-symmetry, disk and sphere configurations of D3-branes are formed in the dual supergravity background. The analytic, canonical metric for these geometries is formulated and the singularity structure is studied. Quarks are introduced into the corresponding field theories using D7-brane probes and the meson spectrum is calculated. For one of the condensate configurations, a mass gap is found and shown analytically to be present in the massless limit. It is also found that there is a stepped spectrum with eigenstate degeneracy in the limit of small quark masses and this result is shown analytically. In the second, similar deformation it is necessary to understand the full D3-D7 brane interaction to study the limit of small quark masses. For quark masses larger than the condensate scale the spectrum is calculated and shown to be discrete as expected.

Hidden role of Maxwell superalgebras in the free differential algebras of D = 4 and D = 11 supergravity

NASA Astrophysics Data System (ADS)

Ravera, Lucrezia

2018-03-01

The purpose of this paper is to show that the so-called Maxwell superalgebra in four dimensions, which naturally involves the presence of a nilpotent fermionic generator, can be interpreted as a hidden superalgebra underlying N=1, {D}=4 supergravity extended to include a 2-form gauge potential associated to a 2-index antisymmetric tensor. In this scenario, the theory is appropriately discussed in the context of Free Differential Algebras (an extension of the Maurer-Cartan equations to involve higher-degree differential forms). The study is then extended to the Free Differential Algebra describing D = 11 supergravity, showing that, also in this case, there exists a super-Maxwell algebra underlying the theory. The same extra spinors dual to the nilpotent fermionic generators whose presence is crucial for writing a supersymmetric extension of the Maxwell algebras, both in the D = 4 and in the D = 11 case, turn out to be fundamental ingredients also to reproduce the D = 4 and D = 11 Free Differential Algebras on ordinary superspace, whose basis is given by the supervielbein. The analysis of the gauge structure of the supersymmetric Free Differential Algebras is carried on taking into account the gauge transformations from the hidden supergroup-manifold associated with the Maxwell superalgebras.

U(1){sub R} mediation from the flux compactification in six dimensions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Hyun Min

We consider a supersymmetric completion of codimension-two branes with nonzero tension in a 6D gauged supergravity. As a consequence, we obtain the football solution with 4D Minkowski space as a new supersymmetric background that preserves 4D N = 1 SUSY. In the presence of brane multiplets, we derive the 4D effective supergravity action for the football background and show that the remaining modulus can be stabilized by a bulk non-perturbative correction with brane uplifting potentials at a zero vacuum energy. We find that the U(1){sub R} mediation can be a dominant source of SUSY breaking for a brane scalar withmore » nonzero R charge.« less

Universal fermionic spectral functions from string theory.

PubMed

Gauntlett, Jerome P; Sonner, Julian; Waldram, Daniel

2011-12-09

We carry out the first holographic calculation of a fermionic response function for a strongly coupled d=3 system with an explicit D=10 or D=11 supergravity dual. By considering the supersymmetry current, we obtain a universal result applicable to all d=3 N=2 SCFTs with such duals. Surprisingly, the spectral function does not exhibit a Fermi surface, despite the fact that the system is at finite charge density. We show that it has a phonino pole and at low frequencies there is a depletion of spectral weight with a power-law scaling which is governed by a locally quantum critical point.

A swamp of non-SUSY vacua

NASA Astrophysics Data System (ADS)

Danielsson, U. H.; Dibitetto, G.; Vargas, S. C.

2017-11-01

We consider known examples of non-supersymmetric AdS7 and AdS4 solutions arising from compactifications of massive type IIA supergravity and study their stability, taking into account the coupling between closed- and open-string sector excitations. Generically, open strings are found to develop modes with masses below the Breitenlohner-Freedman (BF) bound. We comment on the relation with the Weak Gravity Conjecture, and how this analysis may play an important role in examining the validity of non-supersymmetric constructions in string theory.

The D 2 k R 4 invariants of mathcal{N} = 8 supergravity

NASA Astrophysics Data System (ADS)

Freedman, Daniel Z.; Tonni, Erik

2011-04-01

The existence of a linearized SUSY invariant for mathcal{N} = 8 supergravity whose gravitational components are usually called R 4 was established long ago by on-shell super-space arguments. Superspace and string theory methods have also established analogous higher dimensional D 2 k R 4 invariants. However, very little is known about the SUSY completions of these operators which involve other fields of the theory. In this paper we find the detailed component expansion of the linearized R 4 invariant starting from the corresponding superamplitude which generates all component matrix elements of the operator. It is then quite straightforward to extend results to the entire set of D 2 k R 4 operators.

N = 1 supercurrents of eleven-dimensional supergravity

NASA Astrophysics Data System (ADS)

Becker, Katrin; Becker, Melanie; Butter, Daniel; Linch, William D.

2018-05-01

Eleven-dimensional supergravity can be formulated in superspaces locally of the form X × Y where X is 4D N = 1 conformal superspace and Y is an arbitrary 7-manifold admitting a G 2-structure. The eleven-dimensional 3-form and the stable 3-form on Y define the lowest component of a gauge superfield on X × Y that is chiral as a superfield on X. This chiral field is part of a tensor hierarchy giving rise to a superspace Chern-Simons action and its real field strength defines a lifting of the Hitchin functional on Y to the G 2 superspace X × Y . These terms are those of lowest order in a superspace Noether expansion in seven N = 1 conformal gravitino superfields Ψ. In this paper, we compute the O(Ψ) action to all orders in the remaining fields. The eleven-dimensional origin of the resulting non-linear structures is parameterized by the choice of a complex spinor on Y encoding the off-shell 4D N = 1 subalgebra of the eleven-dimensional super-Poincaré algebra.

Boomerang RG flows in M-theory with intermediate scaling

NASA Astrophysics Data System (ADS)

Donos, Aristomenis; Gauntlett, Jerome P.; Rosen, Christopher; Sosa-Rodriguez, Omar

2017-07-01

We construct novel RG flows of D=11 supergravity that asymptotically approach AdS 4 × S 7 in the UV with deformations that break spatial translations in the dual field theory. In the IR the solutions return to exactly the same AdS 4 × S 7 vacuum, with a renormalisation of relative length scales, and hence we refer to the flows as `boomerang RG flows'. For sufficiently large deformations, on the way to the IR the solutions also approach two distinct intermediate scaling regimes, each with hyperscaling violation. The first regime is Lorentz invariant with dynamical exponent z = 1 while the second has z = 5/2. Neither ofthe two intermediatescaling regimesare associatedwith exact hyperscaling violation solutions of D = 11 supergravity. The RG flow solutions are constructed using the four dimensional N = 2 STU gauged supergravity theory with vanishing gauge fields, but non-vanishing scalar and pseudoscalar fields. In the ABJM dual field theory the flows are driven by spatially modulated deformation parameters for scalar and fermion bilinear operators.

Hairy black holes and duality in an extended supergravity model

NASA Astrophysics Data System (ADS)

Anabalón, Andrés; Astefanesei, Dumitru; Gallerati, Antonio; Trigiante, Mario

2018-04-01

We consider a D = 4, N=2 gauged supergravity with an electromagnetic Fayet-Iliopoulos term. We restrict to the uncharged, single dilaton consistent truncation and point out that the bulk Lagrangian is self-dual under electromagnetic duality. Within this truncation, we construct two families of exact hairy black hole solutions, which are asymptotically AdS 4. When a duality transformation is applied on these solutions, they are mapped to two other inequivalent families of hairy black hole solutions. The mixed boundary conditions of the scalar field correspond to adding a triple-trace operator to the dual field theory action. We also show that this truncation contains all the consistent single dilaton truncations of gauged N=8 supergravity with a possible ω-deformation.

Charge orbits of extremal black holes in five-dimensional supergravity

NASA Astrophysics Data System (ADS)

Cerchiai, Bianca L.; Ferrara, Sergio; Marrani, Alessio; Zumino, Bruno

2010-10-01

We derive the U-duality charge orbits, as well as the related moduli spaces, of “large” and “small” extremal black holes in nonmaximal ungauged Maxwell-Einstein supergravities with symmetric scalar manifolds in d=5 space-time dimensions. The stabilizer groups of the various classes of orbits are obtained by determining and solving suitable U-invariant sets of constraints, both in “bare” and “dressed” charge bases, with various methods. After a general treatment of attractors in real special geometry (also considering nonsymmetric cases), the N=2 “magic” theories, as well as the N=2 Jordan symmetric sequence, are analyzed in detail. Finally, the half-maximal (N=4) matter-coupled supergravity is also studied in this context.

Reducing democratic type II supergravity on SU(3) × SU(3) structures

NASA Astrophysics Data System (ADS)

Cassani, Davide

2008-06-01

Type II supergravity on backgrounds admitting SU(3) × SU(3) structure and general fluxes is considered. Using the generalized geometry formalism, we study dimensional reductions leading to N = 2 gauged supergravity in four dimensions, possibly with tensor multiplets. In particular, a geometric formula for the full N = 2 scalar potential is given. Then we implement a truncation ansatz, and derive the complete N = 2 bosonic action. While the NSNS contribution is obtained via a direct dimensional reduction, the contribution of the RR sector is computed starting from the democratic formulation and demanding consistency with the reduced equations of motion.

Black holes and black strings of N = 2, d = 5 supergravity in the H-FGK formalism

NASA Astrophysics Data System (ADS)

Meessen, Patrick; Ortín, Tomás; Perz, Jan; Shahbazi, C. S.

2012-09-01

We study general classes and properties of extremal and non-extremal static black-hole solutions of N = 2, d = 5 supergravity coupled to vector multiplets using the recently proposed H-FGK formalism, which we also extend to static black strings. We explain how to determine the integration constants and physical parameters of the blackhole and black-string solutions. We derive some model-independent statements, including the transformation of non-extremal flow equations to the form of those for the extremal flow. We apply our methods to the construction of example solutions (among others a new extremal string solution of heterotic string theory on K 3 × S 1). In the cases where we have calculated it explicitly, the product of areas of the inner and outer horizon of a non-extremal solution coincides with the square of the moduli-independent area of the horizon of the extremal solution with the same charges.

Conformal anomaly and off-shell extensions of gravity

NASA Astrophysics Data System (ADS)

Meissner, Krzysztof A.; Nicolai, Hermann

2017-08-01

The gauge dependence of the conformal anomaly for spin-3/2 and spin-2 fields in nonconformal supergravities has been a long standing puzzle. In this paper we argue that the "correct" gauge choice is the one that follows from requiring all terms that would imply a violation of the Wess-Zumino consistency condition to be absent in the counterterm, because otherwise the usual link between the anomaly and the one-loop divergence becomes invalid. Remarkably, the "good" choice of gauge is the one that confirms our previous result [K. A. Meissner and H. Nicolai, Phys. Lett. B 772, 169 (2017)., 10.1016/j.physletb.2017.06.031] that a complete cancellation of conformal anomalies in D =4 can only be achieved for N -extended (Poincaré) supergravities with N ≥5 .

Quantum Field Theories Coupled to Supergravity: AdS/CFT and Local Couplings

NASA Astrophysics Data System (ADS)

Große, Johannes

2007-11-01

This article is based on my PhD thesis and covers the following topics: Holographic meson spectra in a dilaton flow background, the mixed Coulomb-Higgs branch in terms of instantons on D7 branes, and a dual description of heavy-light mesons. Moreover, in a second part the conformal anomaly of four dimensional supersymmetric quantum field theories coupled to classical N=1 supergravity is explored in a superfield formulation. The complete basis for the anomaly and consistency conditions, which arise from cohomological considerations, are given. Possible implications for an extension of Zamolodchikov's c-theorem to four dimensional supersymmetric quantum field theories are discussed.

24 +24 real scalar multiplet in four dimensional N =2 conformal supergravity

NASA Astrophysics Data System (ADS)

Hegde, Subramanya; Lodato, Ivano; Sahoo, Bindusar

2018-03-01

Starting from the 48 +48 component multiplet of supercurrents for a rigid N =2 tensor multiplet in four spacetime dimensions, we obtain the transformation of the linearized supergravity multiplet which couples to this supercurrent multiplet. At the linearized level, this 48 +48 component supergravity multiplet decouples into the 24 +24 component linearized standard Weyl multiplet and a 24 +24 component irreducible matter multiplet containing a real scalar field. By a consistent application of the supersymmetry algebra with field-dependent structure constants appropriate to N =2 conformal supergravity, we find the full transformation law for this multiplet in a conformal supergravity background. By performing a suitable field redefinition, we find that the multiplet is a generalization of the flat space multiplet, obtained by Howe et al. in Nucl. Phys. B214, 519 (1983), 10.1016/0550-3213(83)90249-3, to a conformal supergravity background. We also present a set of constraints which can be consistently imposed on this multiplet to obtain a restricted minimal 8 +8 off-shell matter multiplet. We also show, as an example, the precise embedding of the tensor multiplet inside this multiplet.

Ghostbusters in f ( R) supergravity

NASA Astrophysics Data System (ADS)

Fujimori, Toshiaki; Nitta, Muneto; Ohashi, Keisuke; Yamada, Yusuke

2018-05-01

f ( R) supergravity is known to contain a ghost mode associated with higher-derivative terms if it contains R n with n greater than two. We remove the ghost in f ( R) supergravity by introducing auxiliary gauge field to absorb the ghost. We dub this method as the ghostbuster mechanism [1]. We show that the mechanism removes the ghost super-multiplet but also terms including R n with n ≥ 3, after integrating out auxiliary degrees of freedom. For pure supergravity case, there appears an instability in the resultant scalar potential. We then show that the instability of the scalar potential can be cured by introducing matter couplings in such a way that the system has a stable potential.

Automorphic properties of low energy string amplitudes in various dimensions

NASA Astrophysics Data System (ADS)

Green, Michael B.; Russo, Jorge G.; Vanhove, Pierre

2010-04-01

This paper explores the moduli-dependent coefficients of higher-derivative interactions that appear in the low-energy expansion of the four-supergraviton amplitude of maximally supersymmetric string theory compactified on a d torus. These automorphic functions are determined for terms up to order ∂6R4 and various values of d by imposing a variety of consistency conditions. They satisfy Laplace eigenvalue equations with or without source terms, whose solutions are given in terms of Eisenstein series, or more general automorphic functions, for certain parabolic subgroups of the relevant U-duality groups. The ultraviolet divergences of the corresponding supergravity field theory limits are encoded in various logarithms, although the string theory expressions are finite. This analysis includes intriguing representations of SL(d) and SO(d,d) Eisenstein series in terms of toroidally compactified one and two-loop string and supergravity amplitudes.

Abelian tensor hierarchy in 4D N = 1 conformal supergravity

NASA Astrophysics Data System (ADS)

Aoki, Shuntaro; Higaki, Tetsutaro; Yamada, Yusuke; Yokokura, Ryo

2016-09-01

We consider Abelian tensor hierarchy in four-dimensional N = 1 supergravity in the conformal superspace formalism, where the so-called covariant approach is used to antisymmetric tensor fields. We introduce p-form gauge superfields as superforms in the conformal superspace. We solve the Bianchi identities under the constraints for the super-forms. As a result, each of form fields is expressed by a single gauge invariant superfield. We also show the relation between the superspace formalism and the superconformal tensor calculus.

Deformation of N = 4 SYM with varying couplings via fluxes and intersecting branes

NASA Astrophysics Data System (ADS)

Choi, Jaewang; Fernández-Melgarejo, José J.; Sugimoto, Shigeki

2018-03-01

We study deformations of N = 4 supersymmetric Yang-Mills theory with space-time dependent couplings by embedding probe D3-branes in supergravity backgrounds with non-trivial fluxes. The effective action on the world-volume of the D3-branes is analyzed and a map between the deformation parameters and the fluxes is obtained. As an explicit example, we consider D3-branes in a background corresponding to ( p, q) 5-branes intersecting them and show that the effective theory on the D3-branes precisely agrees with the supersymmetric Janus configuration found by Gaiotto and Witten in [1]. D3-branes in an intersecting D3-brane background is also analyzed and the D3-brane effective action reproduces one of the supersymmetric configurations with ISO(1 , 1) × SO(2) × SO(4) symmetry found in our previous paper [2].

Removal of Inclusions from Molten Aluminum by Supergravity Filtration

NASA Astrophysics Data System (ADS)

Song, Gaoyang; Song, Bo; Yang, Zhanbing; Yang, Yuhou; Zhang, Jing

2016-12-01

A new approach to removing inclusions from aluminum melt by supergravity filtration was investigated. The molten aluminum containing MgAl2O4 spinel and coarse Al3Ti particles was isothermally filtered with different gravity coefficients, different filtering times, and various filtering temperatures under supergravity field. When the gravity coefficient G ≥ 50, the alloy samples were divided automatically into two parts: the upper residue and the lower filtered aluminum. All inclusions (MgAl2O4 and Al3Ti particles) were nearly intercepted in the upper residue by filter felt with average pore size of 44.78 μm. The removal efficiencies of oxide inclusions and Al3Ti particles exceeded 98 and 90 pct, respectively, at G ≥ 50, t = 2 minutes, T = 973 K (700 °C). Besides, the yield of purified aluminum was up to 92.1 pct at G = 600, t = 2 minutes, and T = 973 K (700 °C). The calculations of centrifugal pressure indicated that supergravity filtration could effectively overcome the pressure drop without meeting the rigorous requirement of height of molten metal, especially for using the fine-pore filter medium. Moreover, cake-mode filtration was the major mechanism of supergravity filtration of molten metal in this work.

Logarithmic corrections to black hole entropy: the non-BPS branch

NASA Astrophysics Data System (ADS)

Castro, Alejandra; Godet, Victor; Larsen, Finn; Zeng, Yangwenxiao

2018-05-01

We compute the leading logarithmic correction to black hole entropy on the non-BPS branch of 4D N≥2 supergravity theories. This branch corresponds to finite temperature black holes whose extremal limit does not preserve supersymmetry, such as the D0 - D6 system in string theory. Starting from a black hole in minimal Kaluza-Klein theory, we discuss in detail its embedding into N=8 , 6, 4, 2 supergravity, its spectrum of quadratic fluctuations in all these environments, and the resulting quantum corrections. We find that the c-anomaly vanishes only when N≥6 , in contrast to the BPS branch where c vanishes for all N≥2 . We briefly discuss potential repercussions this feature could have in a microscopic description of these black holes.

Unifying Type-II Strings by Exceptional Groups

NASA Astrophysics Data System (ADS)

Arvanitakis, Alex S.; Blair, Chris D. A.

2018-05-01

We construct the exceptional sigma model: a two-dimensional sigma model coupled to a supergravity background in a manifestly (formally) ED (D )-covariant manner. This formulation of the background is provided by exceptional field theory (EFT), which unites the metric and form fields of supergravity in ED (D ) multiplets before compactification. The realization of the symmetries of EFT on the world sheet uniquely fixes the Weyl-invariant Lagrangian and allows us to relate our action to the usual type-IIA fundamental string action and a form of the type-IIB (m , n ) action. This uniqueness "predicts" the correct form of the couplings to gauge fields in both Neveu-Schwarz and Ramond sectors, without invoking supersymmetry.

Black holes with halos

NASA Astrophysics Data System (ADS)

Monten, Ruben; Toldo, Chiara

2018-02-01

We present new AdS4 black hole solutions in N =2 gauged supergravity coupled to vector and hypermultiplets. We focus on a particular consistent truncation of M-theory on the homogeneous Sasaki–Einstein seven-manifold M 111, characterized by the presence of one Betti vector multiplet. We numerically construct static and spherically symmetric black holes with electric and magnetic charges, corresponding to M2 and M5 branes wrapping non-contractible cycles of the internal manifold. The novel feature characterizing these nonzero temperature configurations is the presence of a massive vector field halo. Moreover, we verify the first law of black hole mechanics and we study the thermodynamics in the canonical ensemble. We analyze the behavior of the massive vector field condensate across the small-large black hole phase transition and we interpret the process in the dual field theory.

Super-BMS3 algebras from {N}=2 flat supergravities

NASA Astrophysics Data System (ADS)

Lodato, Ivano; Merbis, Wout

2016-11-01

We consider two possible flat space limits of three dimensional {N}=(1, 1) AdS supergravity. They differ by how the supercharges are scaled with the AdS radius ℓ: the first limit (democratic) leads to the usual super-Poincaré theory, while a novel `twisted' theory of supergravity stems from the second (despotic) limit. We then propose boundary conditions such that the asymptotic symmetry algebras at null infinity correspond to supersymmetric extensions of the BMS algebras previously derived in connection to non- and ultra-relativistic limits of the {N}=(1, 1) Virasoro algebra in two dimensions. Finally, we study the supersymmetric energy bounds and find the explicit form of the asymptotic and global Killing spinors of supersymmetric solutions in both flat space supergravity theories.

Rigid supersymmetric backgrounds of 3-dimensional Newton-Cartan supergravity

DOE PAGES

Knodel, Gino; Lisbao, Pedro; Liu, James T.

2016-06-06

Recently, a non-relativistic off-shell formulation of three dimensional Newton-Cartan supergravity was proposed as the c → ∞ limit of three dimensional N = 2 super-gravity [1]. Here in the present paper we study supersymmetric backgrounds within this theory. Using integrability constraints for the non-relativistic Killing spinor equations, we explicitly construct all maximally supersymmetric solutions, which admit four supercharges. In addition to these solutions, there aremore » $$\\frac{1}{2}$$ -BPS solutions with reduced supersymmetry. We give explicit examples of such backgrounds and derive necessary conditions for backgrounds preserving two supercharges. Finally, we address how supersymmetric backgrounds of N = 2 supergravity are connected to the solutions found here in the c → ∞ limit.« less

Conformal supergravity in five dimensions: new approach and applications

NASA Astrophysics Data System (ADS)

Butter, Daniel; Kuzenko, Sergei M.; Novak, Joseph; Tartaglino-Mazzucchelli, Gabriele

2015-02-01

We develop a new off-shell formulation for five-dimensional (5D) conformal supergravity obtained by gauging the 5D superconformal algebra in superspace. An important property of the conformal superspace introduced is that it reduces to the super-conformal tensor calculus (formulated in the early 2000's) upon gauging away a number of superfluous fields. On the other hand, a different gauge fixing reduces our formulation to the SU(2) superspace of arXiv:0802.3953, which is suitable to describe the most general off-shell supergravity-matter couplings. Using the conformal superspace approach, we show how to reproduce practically all off-shell constructions derived so far, including he supersymmetric extensions of R 2 terms, thus demonstrating the power of our formulation. Furthermore, we construct for the first time a supersymmetric completion of the Ricci tensor squared term using the standard Weyl multiplet coupled to an off-shell vector multiplet. In addition, we present several procedures to generate higher-order off-shell invariants in supergravity, including higher-derivative ones. The covariant projective multiplets proposed in arXiv:0802.3953 are lifted to conformal superspace, and a manifestly superconformal action principle is given. We also introduce unconstrained prepotentials for the vector multiplet, the multiplet (i.e., the linear multiplet without central charge) and multiplets, with n = 0 , 1 , . . . Superform formulations are given for the BF action and the non-abelian Chern-Simons action. Finally, we describe locally supersymmetric theories with gauged central charge in conformal superspace.

Exceptional field theories, superparticles in an enlarged 11D superspace and higher spin theories

NASA Astrophysics Data System (ADS)

Bandos, Igor

2017-12-01

Recently proposed exceptional field theories (EFTs) making manifest the duality E n (n) symmetry, first observed as nonlinearly realized symmetries of the maximal d = 3 , 4 , . . . , 9 supergravity (n = 11 - d) and containing 11D and type IIB supergravity as sectors, were formulated in enlarged spacetimes. In the case of E 7 (7) EFT such an enlarged spacetime can be identified with the bosonic body of the d = 4 central charge superspace Σ (60 | 32), the N = 8 d = 4 superspace completed by 56 additional bosonic coordinates associated to central charges of the maximal d = 4 supersymmetry algebra. In this paper we show how the hypothesis on the relation of all the known E n (n) EFTs, including n = 8, with supersymmetry leads to the conjecture on existence of 11D exceptional field theory living in 11D tensorial central charge superspace Σ (528 | 32) and underlying all the E n (n) EFTs with n = 2 , . . . , 8, and probably the double field theory (DFT). We conjecture the possible form of the section conditions of such an 11D EFT and show that quite generic solutions of these can be generated by superparticle models the ground states of which preserve from one half to all but one supersymmetry. The properties of these superparticle models are briefly discussed. We argue that, upon quantization, their quantum states should describe free massless non-conformal higher spin fields in D = 11. We also discuss some relevant representations of the M-theory superalgebra which, in the present context, describes supersymmetry of the 11D EFT.

Non-analytic terms from nested divergences in maximal supergravity

NASA Astrophysics Data System (ADS)

Basu, Anirban

2016-07-01

The {D}4{{ R }}4 and {D}6{{ R }}4 coefficient functions in the effective action of type II string theory compactified on T d contain terms of the form {{ E }}1{{ln}}{g}d and {{ E }}2{({{ln}}{g}d)}2 in specific dimensions, where g d is the T-duality invariant string coupling, and {{ E }}1 and {{ E }}2 are U-duality invariant coefficient functions. We derive these non-analytic terms from nested ultraviolet divergences in two and three loop maximal supergravity. For the {D}4{{ R }}4 coupling, the contribution involves {{ E }}{{ R }4}{{ln}}{g}d, while for the {D}6{{ R }}4 coupling, it involves {{ E }}{{ R }4}{{ln}}{g}d, {{ E }}{D2{{ R }}4}{({{ln}}{g}d)}2 and {{ E }}{D4{{ R }}4}{{ln}}{g}d; where {{ E }}{{ R }4}, {{ E }}{D2{{ R }}4} and {{ E }}{D4{{ R }}4} are the {{ R }}4, {D}2{{ R }}4 and {D}4{{ R }}4 coefficient functions respectively. The contribution from {{ E }}{D2{{ R }}4}, the coefficient function of an amplitude that vanishes onshell, arises from a two loop nested subdivergence of the three loop amplitude.

Butterfly effect in 3D gravity

NASA Astrophysics Data System (ADS)

Qaemmaqami, Mohammad M.

2017-11-01

We study the butterfly effect by considering shock wave solutions near the horizon of the anti-de Sitter black hole in some three-dimensional gravity models including 3D Einstein gravity, minimal massive 3D gravity, new massive gravity, generalized massive gravity, Born-Infeld 3D gravity, and new bigravity. We calculate the butterfly velocities of these models and also we consider the critical points and different limits in some of these models. By studying the butterfly effect in the generalized massive gravity, we observe a correspondence between the butterfly velocities and right-left moving degrees of freedom or the central charges of the dual 2D conformal field theories.

Chiral superparticle and the full set of (1,0) supergravity constraints

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deriglazov, A.A.

1993-03-10

The author presents BFV quantization of manifestly Lorentz-covariant chiral particle action. Lagrangians for (1,1), (1,0), (0,1) chiral superparticles (CSP) invariant under the local Siegel-type transformations are considered; the mechanism of closing of local Siegel k-symmetry algebra in Lagrangian formulation for the (1,0) CSP is suggested. The full set of (1,0) supergravity constraints is obtained from the requirement of preserving local symmetries in a curved background. The possibility of extending the results to D = 10 case is discussed.

Open/closed string duality and relativistic fluids

NASA Astrophysics Data System (ADS)

Niarchos, Vasilis

2016-07-01

We propose an open/closed string duality in general backgrounds extending previous ideas about open string completeness by Ashoke Sen. Our proposal sets up a general version of holography that works in gravity as a tomographic principle. We argue, in particular, that previous expectations of a supergravity/Dirac-Born-Infeld (DBI) correspondence are naturally embedded in this conjecture and can be tested in a well-defined manner. As an example, we consider the correspondence between open string field theories on extremal D-brane setups in flat space in the large-N , large 't Hooft limit, and asymptotically flat solutions in ten-dimensional type II supergravity. We focus on a convenient long-wavelength regime, where specific effects of higher-spin open string modes can be traced explicitly in the dual supergravity computation. For instance, in this regime we show how the full Abelian DBI action arises from supergravity as a straightforward reformulation of relativistic hydrodynamics. In the example of a (2 +1 )-dimensional open string theory this reformulation involves an Abelian Hodge duality. We also point out how different deformations of the DBI action, related to higher-derivative corrections and non-Abelian effects, can arise in this context as deformations in corresponding relativistic hydrodynamics.

Testing no-scale supergravity with the Fermi Space Telescope LAT

NASA Astrophysics Data System (ADS)

Li, Tianjun; Maxin, James A.; Nanopoulos, Dimitri V.; Walker, Joel W.

2014-05-01

We describe a methodology for testing no-scale supergravity by the LAT instrument onboard the Fermi Space Telescope via observation of gamma ray emissions from lightest supersymmetric (SUSY) neutralino annihilations. For our test vehicle we engage the framework of the SUSY grand unified model no-scale flipped SU(5) with extra vector-like flippon multiplets derived from F-theory, known as { F}-SU(5). We show that through compression of the light stau and light bino neutralino mass difference, where internal bremsstrahlung photons give a dominant contribution, the photon yield from annihilation of SUSY dark matter can be elevated to a number of events potentially observable by the Fermi-LAT in the coming years. Likewise, the increased yield in no-scale { F}-SU(5) may also have rendered the existing observation of a 133 GeV monochromatic gamma ray line visible, if additional data should exclude systematic or statistical explanations. The question of intensity aside, no-scale { F}-SU(5) can indeed provide a natural weakly interacting massive particle candidate with a mass in the correct range to yield γγ and γZ emission lines at mχ ˜ 133 GeV and mχ ˜ 145 GeV, respectively. Additionally, we elucidate the emerging empirical connection between recent Planck satellite data and no-scale supergravity cosmological models which mimic the Starobinsky model of inflation. Together, these experiments furnish rich alternate avenues for testing no-scale { F}-SU(5), and similarly structured models, the results of which may lend independent credence to observations made at the Large Hadron Collider.

Geometric low-energy effective action in a doubled spacetime

NASA Astrophysics Data System (ADS)

Ma, Chen-Te; Pezzella, Franco

2018-05-01

The ten-dimensional supergravity theory is a geometric low-energy effective theory and the equations of motion for its fields can be obtained from string theory by computing β functions. With d compact dimensions, an O (d , d ; Z) geometric structure can be added to it giving the supergravity theory with T-duality manifest. In this paper, this is constructed through the use of a suitable star product whose role is the one to implement the weak constraint on the fields and the gauge parameters in order to have a closed gauge symmetry algebra. The consistency of the action here proposed is based on the orthogonality of the momenta associated with fields in their triple star products in the cubic terms defined for d ≥ 1. This orthogonality holds also for an arbitrary number of star products of fields for d = 1. Finally, we extend our analysis to the double sigma model, non-commutative geometry and open string theory.

Higher derivative couplings in theories with sixteen supersymmetries

DOE PAGES

Lin, Ying -Hsuan; Shao, Shu -Heng; Yin, Xi; ...

2015-12-15

We give simple arguments for new non-renormalization theorems on higher derivative couplings of gauge theories to supergravity, with sixteen supersymmetries, by considerations of brane-bulk superamplitudes. This leads to some exact results on the effective coupling of D3-branes in type IIB string theory. As a result, we also derive exact results on higher dimensional operators in the torus compactification of the six dimensional (0, 2) superconformal theory.

Mass deformations of 5d SCFTs via holography

NASA Astrophysics Data System (ADS)

Gutperle, Michael; Kaidi, Justin; Raj, Himanshu

2018-02-01

Using six-dimensional Euclidean F (4) gauged supergravity we construct a holographic renormalization group flow for a CFT on S 5. Numerical solutions to the BPS equations are obtained and the free energy of the theory on S 5 is determined holographically by calculation of the renormalized on-shell supergravity action. In the process, we deal with subtle issues such as holographic renormalization and addition of finite counterterms. We then propose a candidate field theory dual to these solutions. This tentative dual is a supersymmetry-preserving deformation of the strongly-coupled non-Lagrangian SCFT derived from the D4-D8 system in string theory. In the IR, this theory is a mass deformation of a USp(2 N ) gauge theory. A localization calculation of the free energy is performed for this IR theory, which for reasonably small values of the deformation parameter is found to have the same qualitative behaviour as the holographic free energy.

Starobinsky-Like Inflation and Running Vacuum in the Context of Supergravity

NASA Astrophysics Data System (ADS)

Basilakos, Spyros; Mavromatos, Nick; Solà, Joan

2016-07-01

We describe the primeval inflationary phase of the early Universe within a quantum field theoretical (QFT) framework that can be viewed as the effective action of vacuum decay in the early times. Interestingly enough, the model accounts for the "graceful exit" of the inflationary phase into the standard radiation regime. The underlying QFT framework considered here is Supergravity (SUGRA), more specifically an existing formulation in which the Starobinsky-type inflation (de-Sitter background) emerges from the quantum corrections to the effective action after integrating out the gravitino fields in their (dynamically induced) massive phase. We also demonstrate that the structure of the effective action in this model is consistent with the generic idea of renormalization group (RG) running of the cosmological parameters, specifically it follows from the corresponding RG equation for the vacuum energy density as a function of the Hubble rate, $\\rho_{\\Lambda}(H)$. Overall our combined approach amounts to a concrete-model realization of inflation triggered by vacuum decay in a fundamental physics context which, as it turns out, can also be extended for the remaining epochs of the cosmological evolution until the current dark energy era.

Rapid Separation of Copper Phase and Iron-Rich Phase From Copper Slag at Low Temperature in a Super-Gravity Field

NASA Astrophysics Data System (ADS)

Lan, Xi; Gao, Jintao; Huang, Zili; Guo, Zhancheng

2018-03-01

A novel approach for quickly separating a metal copper phase and iron-rich phase from copper slag at low temperature is proposed based on a super-gravity method. The morphology and mineral evolution of the copper slag with increasing temperature were studied using in situ high-temperature confocal laser scanning microscopy and ex situ scanning electron microscopy and X-ray diffraction methods. Fe3O4 particles dispersed among the copper slag were transformed into FeO by adding an appropriate amount of carbon as a reducing agent, forming the slag melt with SiO2 at low temperature and assisting separation of the copper phase from the slag. Consequently, in a super-gravity field, the metallic copper and copper matte were concentrated as the copper phase along the super-gravity direction, whereas the iron-rich slag migrated in the opposite direction and was quickly separated from the copper phase. Increasing the gravity coefficient (G) significantly enhanced the separation efficiency. After super-gravity separation at G = 1000 and 1473 K (1200 °C) for 3 minutes, the mass fraction of Cu in the separated copper phase reached 86.11 wt pct, while that in the separated iron-rich phase was reduced to 0.105 wt pct. The recovery ratio of Cu in the copper phase was as high as up to 97.47 pct.

Rapid Separation of Copper Phase and Iron-Rich Phase From Copper Slag at Low Temperature in a Super-Gravity Field

NASA Astrophysics Data System (ADS)

Lan, Xi; Gao, Jintao; Huang, Zili; Guo, Zhancheng

2018-06-01

A novel approach for quickly separating a metal copper phase and iron-rich phase from copper slag at low temperature is proposed based on a super-gravity method. The morphology and mineral evolution of the copper slag with increasing temperature were studied using in situ high-temperature confocal laser scanning microscopy and ex situ scanning electron microscopy and X-ray diffraction methods. Fe3O4 particles dispersed among the copper slag were transformed into FeO by adding an appropriate amount of carbon as a reducing agent, forming the slag melt with SiO2 at low temperature and assisting separation of the copper phase from the slag. Consequently, in a super-gravity field, the metallic copper and copper matte were concentrated as the copper phase along the super-gravity direction, whereas the iron-rich slag migrated in the opposite direction and was quickly separated from the copper phase. Increasing the gravity coefficient (G) significantly enhanced the separation efficiency. After super-gravity separation at G = 1000 and 1473 K (1200 °C) for 3 minutes, the mass fraction of Cu in the separated copper phase reached 86.11 wt pct, while that in the separated iron-rich phase was reduced to 0.105 wt pct. The recovery ratio of Cu in the copper phase was as high as up to 97.47 pct.

Habemus superstratum! A constructive proof of the existence of superstrata

NASA Astrophysics Data System (ADS)

Bena, Iosif; Giusto, Stefano; Russo, Rodolfo; Shigemori, Masaki; Warner, Nicholas P.

2015-05-01

We construct the first example of a superstratum: a class of smooth horizonless supergravity solutions that are parameterized by arbitrary continuous functions of (at least) two variables and have the same charges as the supersymmetric D1-D5-P black hole. We work in Type IIB string theory on T 4 or K3 and our solutions involve a subset of fields that can be described by a six-dimensional supergravity with two tensor multiplets. The solutions can thus be constructed using a linear structure, and we give an explicit recipe to start from a superposition of modes specified by an arbitrary function of two variables and impose regularity to obtain the full horizonless solutions in closed form. We also give the precise CFT description of these solutions and show that they are not dual to descendants of chiral primaries. They are thus much more general than all the known solutions whose CFT dual is precisely understood. Hence our construction represents a substantial step toward the ultimate goal of constructing the fully generic superstratum that can account for a finite fraction of the entropy of the three-charge black hole in the regime of parameters where the classical black hole solution exists.

On classical de Sitter and Minkowski solutions with intersecting branes

NASA Astrophysics Data System (ADS)

Andriot, David

2018-03-01

Motivated by the connection of string theory to cosmology or particle physics, we study solutions of type II supergravities having a four-dimensional de Sitter or Minkowski space-time, with intersecting D p -branes and orientifold O p -planes. Only few such solutions are known, and we aim at a better characterisation. Modulo a few restrictions, we prove that there exists no classical de Sitter solution for any combination of D 3/ O 3 and D 7/ O 7, while we derive interesting constraints for intersecting D 5/ O 5 or D 6/ O 6, or combinations of D 4/ O 4 and D 8/ O 8. Concerning classical Minkowski solutions, we understand some typical features, and propose a solution ansatz. Overall, a central information appears to be the way intersecting D p / O p overlap each other, a point we focus on.

Some finite terms from ladder diagrams in three and four loop maximal supergravity

NASA Astrophysics Data System (ADS)

Basu, Anirban

2015-10-01

We consider the finite part of the leading local interactions in the low energy expansion of the four graviton amplitude from the ladder skeleton diagrams in maximal supergravity on T 2, at three and four loops. At three loops, we express the {D}8{{R}}4 and {D}10{{R}}4 amplitudes as integrals over the moduli space of an underlying auxiliary geometry. These amplitudes are evaluated exactly for special values of the the moduli of the auxiliary geometry, where the integrand simplifies. We also perform a similar analysis for the {D}8{{R}}4 amplitude at four loops that arise from the ladder skeleton diagrams for a special value of a parameter in the moduli space of the auxiliary geometry. While the dependence of the amplitudes on the volume of the T 2 is very simple, the dependence on the complex structure of the T 2 is quite intricate. In some of the cases, the amplitude consists of terms each of which factorizes into a product of two {SL}(2,{{Z}}) invariant modular forms. While one of the factors is a non-holomorphic Eisenstein series, the other factor splits into a sum of modular forms each of which satisfies a Poisson equation on moduli space with source terms that are bilinear in the Eisenstein series. This leads to several possible perturbative contributions unto genus 5 in type II string theory on S1. Unlike the one and two loop supergravity analysis, these amplitudes also receive non-perturbative contributions from bound states of three D-(anti)instantons in the IIB theory.

Extremal Correlators in the Ads/cft Correspondence

NASA Astrophysics Data System (ADS)

D'Hoker, Eric; Freedman, Daniel Z.; Mathur, Samir D.; Matusis, Alec; Rastelli, Leonardo

The non-renormalization of the 3-point functions

The 6D superswirl

NASA Astrophysics Data System (ADS)

Parameswaran, S. L.; Tasinato, G.; Zavala, I.

2006-03-01

We present a novel supersymmetric solution to a nonlinear sigma model coupled to supergravity. The solution represents a static, supersymmetric, codimension-two object, which is different to the familiar cosmic strings. In particular, we consider 6D chiral gauged supergravity, whose spectrum contains a number of hypermultiplets. The scalar components of the hypermultiplet are charged under a gauge field, and supersymmetry implies that they experience a simple paraboloid-like (or 2D infinite well) potential, which is minimised when they vanish. Unlike conventional vortices, the energy density of our configuration is not localized to a string-like core. The solutions have two timelike singularities in the internal manifold, which provide the necessary boundary conditions to ensure that the scalars do not lie at the minimum of their potential. The 4D spacetime is flat, and the solution is a continuous deformation of the so-called "rugby ball" solution, which has been studied in the context of the cosmological constant problem. It represents an unexpected class of supersymmetric solutions to the 6D theory, which have gravity, gauge fluxes and hyperscalars all active in the background.

I in generalized supergravity

NASA Astrophysics Data System (ADS)

Araujo, T.; Ó Colgáin, E.; Sakamoto, J.; Sheikh-Jabbari, M. M.; Yoshida, K.

2017-11-01

We showed in previous work that for homogeneous Yang-Baxter (YB) deformations of AdS_5× S^5 the open string metric and coupling and as a result the closed string density e^{-2 Φ } √{g} remain undeformed. In this work, in addition to extending these results to the deformation associated with the modified CYBE or η -deformation, we identify the Page forms as the open string counterpart for RR fields and demonstrate case by case that the non-zero Page forms remain invariant under YB deformations. We give a physical meaning to the Killing vector I of generalized supergravity and show for all YB deformations: (1) I appears as a current for the center of mass motion on the worldvolume of a D-brane probing the background, (2) I is equal to the divergence of the noncommutativity parameter, (3) I exhibits "holographic" behavior where the radial component of I vanishes at the AdS boundary and (4) in pure spinor formalism I is related to a certain state in the BRST cohomology.

An infinite swampland of U(1) charge spectra in 6D supergravity theories

NASA Astrophysics Data System (ADS)

Taylor, Washington; Turner, Andrew P.

2018-06-01

We analyze the anomaly constraints on 6D supergravity theories with a single abelian U(1) gauge factor. For theories with charges restricted to q = ±1 , ±2 and no tensor multiplets, anomaly-free models match those models that can be realized from F-theory compactifications almost perfectly. For theories with tensor multiplets or with larger charges, the F-theory constraints are less well understood. We show, however, that there is an infinite class of distinct massless charge spectra in the "swampland" of theories that satisfy all known quantum consistency conditions but do not admit a realization through F-theory or any other known approach to string compactification. We also compare the spectra of charged matter in abelian theories with those that can be realized from breaking nonabelian SU(2) and higher rank gauge symmetries.

Massively parallel implementation of 3D-RISM calculation with volumetric 3D-FFT.

PubMed

Maruyama, Yutaka; Yoshida, Norio; Tadano, Hiroto; Takahashi, Daisuke; Sato, Mitsuhisa; Hirata, Fumio

2014-07-05

A new three-dimensional reference interaction site model (3D-RISM) program for massively parallel machines combined with the volumetric 3D fast Fourier transform (3D-FFT) was developed, and tested on the RIKEN K supercomputer. The ordinary parallel 3D-RISM program has a limitation on the number of parallelizations because of the limitations of the slab-type 3D-FFT. The volumetric 3D-FFT relieves this limitation drastically. We tested the 3D-RISM calculation on the large and fine calculation cell (2048(3) grid points) on 16,384 nodes, each having eight CPU cores. The new 3D-RISM program achieved excellent scalability to the parallelization, running on the RIKEN K supercomputer. As a benchmark application, we employed the program, combined with molecular dynamics simulation, to analyze the oligomerization process of chymotrypsin Inhibitor 2 mutant. The results demonstrate that the massive parallel 3D-RISM program is effective to analyze the hydration properties of the large biomolecular systems. Copyright © 2014 Wiley Periodicals, Inc.

Supergravity contributions to inflation in models with non-minimal coupling to gravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Das, Kumar; Dutta, Koushik; Domcke, Valerie, E-mail: kumar.das@saha.ac.in, E-mail: valerie.domcke@apc.univ-paris7.fr, E-mail: koushik.dutta@saha.ac.in

2017-03-01

This paper provides a systematic study of supergravity contributions relevant for inflationary model building in Jordan frame supergravity. In this framework, canonical kinetic terms in the Jordan frame result in the separation of the Jordan frame scalar potential into a tree-level term and a supergravity contribution which is potentially dangerous for sustaining inflation. We show that if the vacuum energy necessary for driving inflation originates dominantly from the F-term of an auxiliary field (i.e. not the inflaton), the supergravity corrections to the Jordan frame scalar potential are generically suppressed. Moreover, these supergravity contributions identically vanish if the superpotential vanishes alongmore » the inflationary trajectory. On the other hand, if the F-term associated with the inflaton dominates the vacuum energy, the supergravity contributions are generically comparable to the globally supersymmetric contributions. In addition, the non-minimal coupling to gravity inherent to Jordan frame supergravity significantly impacts the inflationary model depending on the size and sign of this coupling. We discuss the phenomenology of some representative inflationary models, and point out the relation to the recently much discussed cosmological 'attractor' models.« less

Correlation functions in the D1-D5 orbifold CFT

NASA Astrophysics Data System (ADS)

i Tormo, Joan Garcia; Taylor, Marika

2018-06-01

The D1-D5 system has an orbifold point in its moduli space, at which it may be described by an N = (4,4) supersymmetric sigma model with target space M N /S( N) where M is T^4 or K3. In this paper we consider correlation functions involving chiral operators constructed from twist fields: we find explicit expressions for processes involving a twist n operator joining n twist operators of arbitrary twist. These expressions are universal, in that they are independent of the choice of M , and the final results can be expressed in a compact form. We explain how these results are relevant to the black hole microstate programme: one point functions of chiral operators can be used to reconstruct AdS3 near horizon regions of D1-D5 microstates and to match microstates constructed in supergravity with the CFT.

Mass-deformed ABJM and black holes in AdS4

NASA Astrophysics Data System (ADS)

Bobev, Nikolay; Min, Vincent S.; Pilch, Krzysztof

2018-03-01

We find a class of new supersymmetric dyonic black holes in four-dimensional maximal gauged supergravity which are asymptotic to the SU(3) × U(1) invariant AdS4 Warner vacuum. These black holes can be embedded in eleven-dimensional supergravity where they describe the backreaction of M2-branes wrapped on a Riemann surface. The holographic dual description of these supergravity backgrounds is given by a partial topological twist on a Riemann surface of a three-dimensional N=2 SCFT that is obtained by a mass-deformation of the ABJM theory. We compute explicitly the topologically twisted index of this SCFT and show that it accounts for the entropy of the black holes.

Exact solutions in 3D new massive gravity.

PubMed

Ahmedov, Haji; Aliev, Alikram N

2011-01-14

We show that the field equations of new massive gravity (NMG) consist of a massive (tensorial) Klein-Gordon-type equation with a curvature-squared source term and a constraint equation. We also show that, for algebraic type D and N spacetimes, the field equations of topologically massive gravity (TMG) can be thought of as the "square root" of the massive Klein-Gordon-type equation. Using this fact, we establish a simple framework for mapping all types D and N solutions of TMG into NMG. Finally, we present new examples of types D and N solutions to NMG.

Exact Solutions in 3D New Massive Gravity

NASA Astrophysics Data System (ADS)

Ahmedov, Haji; Aliev, Alikram N.

2011-01-01

We show that the field equations of new massive gravity (NMG) consist of a massive (tensorial) Klein-Gordon-type equation with a curvature-squared source term and a constraint equation. We also show that, for algebraic type D and N spacetimes, the field equations of topologically massive gravity (TMG) can be thought of as the “square root” of the massive Klein-Gordon-type equation. Using this fact, we establish a simple framework for mapping all types D and N solutions of TMG into NMG. Finally, we present new examples of types D and N solutions to NMG.

The Casimir effect in rugby-ball type flux compactifications

NASA Astrophysics Data System (ADS)

Minamitsuji, M.

2008-04-01

We discuss volume stabilization in a 6D braneworld model based on 6D supergravity theory. The internal space is compactified by magnetic flux and contains codimension two 3-branes (conical singularities) as its boundaries. In general the external 4D spacetime is warped and in the unwrapped limit the shape of the internal space looks like a 'rugby ball'. The size of the internal space is not fixed due to the scale invariance of the supergravity theory. We discuss the possibility of volume stabilization by the Casimir effect for a massless, minimally coupled bulk scalar field. The main obstacle in studying this case is that the brane (conical) part of the relevant heat kernel coefficient (a6) has not been formulated. Thus as a first step, we consider the 4D analog model with boundary codimension two 1-branes. The spacetime structure of the 4D model is very similar to that of the original 6D model, where now the relevant heat kernel coefficient is well known. We derive the one-loop effective potential induced by a scalar field in the bulk by employing zeta function regularization with heat kernel analysis. As a result, the volume is stabilized for most possible choices of the parameters. Especially, for a larger degree of warping, our results imply that a large hierarchy between the mass scales and a tiny amount of effective cosmological constant can be realized on the brane. In the non-warped limit the ratio tends to converge to the same value, independently of the bulk gauge coupling constant. Finally, we will analyze volume stabilization in the original model 6D by employing the same mode-sum technique.

NASA Spacecraft Captures 3-D View of Massive Australian Wildfire

NASA Image and Video Library

2013-02-05

This 3-D view was created from data acquired Feb. 4, 2013 by NASA Terra spacecraft showing a massive wildfire which damaged Australia largest optical astronomy facility, the Siding Spring Observatory.

Supersymmetric Yang-Mills theory on conformal supergravity backgrounds in ten dimensions

NASA Astrophysics Data System (ADS)

de Medeiros, Paul; Figueroa-O'Farrill, José

2016-03-01

We consider bosonic supersymmetric backgrounds of ten-dimensional conformal supergravity. Up to local conformal isometry, we classify the maximally supersymmetric backgrounds, determine their conformal symmetry superalgebras and show how they arise as near-horizon geometries of certain half-BPS backgrounds or as a plane-wave limit thereof. We then show how to define Yang-Mills theory with rigid supersymmetry on any supersymmetric conformal supergravity background and, in particular, on the maximally supersymmetric backgrounds. We conclude by commenting on a striking resemblance between the supersymmetric backgrounds of ten-dimensional conformal supergravity and those of eleven-dimensional Poincaré supergravity.

One-loop supergravity on AdS 4 × S 7/Z k and comparison with ABJM theory

DOE PAGES

Liu, James T.; Zhao, Wenli

2016-11-18

The large-N limit of ABJM theory is holographically dual to M-theory on AdS 4 × S 7/Z k. The 3-sphere partition function has been obtained via localization, and its leading behavior F ABJM (0) ~ k 1/2N 3/2 is exactly reproduced in the dual theory by tree-level supergravity. In this paper, we extend this comparison to the sub-leading O(N 0) order by computing the one-loop supergravity free energy as a function of k and comparing it with the ABJM result. Curiously, we find that the expressions do not match, with F SUGRA (1)~k 6, while F ABJM (1)~ k 2.more » Finally, this suggests that the low-energy approximation Z M-theory = Z SUGRA breaks down at one-loop order.« less

Anisotropic D3-D5 black holes with unquenched flavors

NASA Astrophysics Data System (ADS)

Penín, José Manuel; Ramallo, Alfonso V.; Zoakos, Dimitrios

2018-02-01

We construct a black hole geometry generated by the intersection of N c color D3- branes and N f flavor D5-branes along a 2+1 dimensional subspace. Working in the Veneziano limit in which N f is large and distributing homogeneously the D5-branes in the internal space, we calculate the solution of the equations of motion of supergravity plus sources which includes the backreaction of the flavor branes. The solution is analytic and dual to a 2+1 dimensional defect in a 3+1 dimensional gauge theory, with N f massless hypermultiplets living in the defect. The smeared background we obtain can be regarded as the holographic realization of a multilayered system. We study the thermodynamics of the resulting spatially anisotropic geometry and compute the first and second order transport coefficients for perturbations propagating along the defect. We find that, in our system, the dynamics of excitations within a layer can be described by a stack of effective D2-branes.

Scale invariance of the η-deformed AdS5 × S5 superstring, T-duality and modified type II equations

NASA Astrophysics Data System (ADS)

Arutyunov, G.; Frolov, S.; Hoare, B.; Roiban, R.; Tseytlin, A. A.

2016-02-01

We consider the ABF background underlying the η-deformed AdS5 ×S5 sigma model. This background fails to satisfy the standard IIB supergravity equations which indicates that the corresponding sigma model is not Weyl invariant, i.e. does not define a critical string theory in the usual sense. We argue that the ABF background should still define a UV finite theory on a flat 2d world-sheet implying that the η-deformed model is scale invariant. This property follows from the formal relation via T-duality between the η-deformed model and the one defined by an exact type IIB supergravity solution that has 6 isometries albeit broken by a linear dilaton. We find that the ABF background satisfies candidate type IIB scale invariance conditions which for the R-R field strengths are of the second order in derivatives. Surprisingly, we also find that the ABF background obeys an interesting modification of the standard IIB supergravity equations that are first order in derivatives of R-R fields. These modified equations explicitly depend on Killing vectors of the ABF background and, although not universal, they imply the universal scale invariance conditions. Moreover, we show that it is precisely the non-isometric dilaton of the T-dual solution that leads, after T-duality, to modification of type II equations from their standard form. We conjecture that the modified equations should follow from κ-symmetry of the η-deformed model. All our observations apply also to η-deformations of AdS3 ×S3 ×T4and AdS2 ×S2 ×T6models.

Scale invariance of the η-deformed AdS 5 × S 5 superstring, T-duality and modified type II equations

DOE PAGES

Arutyunov, G.; Frolov, S.; Hoare, B.; ...

2015-12-23

We consider the ABF background underlying the η-deformed AdS 5 × S 5 sigma model. This background fails to satisfy the standard IIB supergravity equations which indicates that the corresponding sigma model is not Weyl invariant, i.e. does not define a critical string theory in the usual sense. We argue that the ABF background should still define a UV finite theory on a flat 2d world-sheet implying that the η-deformed model is scale invariant. This property follows from the formal relation via T-duality between the η-deformed model and the one defined by an exact type IIB supergravity solution that hasmore » 6 isometries albeit broken by a linear dilaton. We find that the ABF background satisfies candidate type IIB scale invariance conditions which for the R–R field strengths are of the second order in derivatives. Surprisingly, we also find that the ABF background obeys an interesting modification of the standard IIB supergravity equations that are first order in derivatives of R–R fields. These modified equations explicitly depend on Killing vectors of the ABF background and, although not universal, they imply the universal scale invariance conditions. Moreover, we show that it is precisely the non-isometric dilaton of the T-dual solution that leads, after T-duality, to modification of type II equations from their standard form. We conjecture that the modified equations should follow from κ-symmetry of the η-deformed model. All our observations apply also to η-deformations of AdS 3 × S 3 × T 4 and AdS 2 × S 2 × T 6 models.« less

Habemus superstratum! A constructive proof of the existence of superstrata

DOE PAGES

Bena, Iosif; Giusto, Stefano; Russo, Rodolfo; ...

2015-05-21

Here, we construct the first example of a superstratum: a class of smooth horizonless supergravity solutions that are parameterized by arbitrary continuous functions of (at least) two variables and have the same charges as the supersymmetric D1-D5-P black hole. We work in Type IIB string theory on T 4 or K 3 and our solutions involve a subset of fields that can be described by a six-dimensional supergravity with two tensor multiplets. The solutions can thus be constructed using a linear structure, and we give an explicit recipe to start from a superposition of modes specified by an arbitrary functionmore » of two variables and impose regularity to obtain the full horizonless solutions in closed form. We also give the precise CFT description of these solutions and show that they are not dual to descendants of chiral primaries. They are thus much more general than all the known solutions whose CFT dual is precisely understood. Hence our construction represents a substantial step toward the ultimate goal of constructing the fully generic superstratum that can account for a finite fraction of the entropy of the three-charge black hole in the regime of parameters where the classical black hole solution exists.« less

Brane Inflation, Solitons and Cosmological Solutions: I

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, P.

2005-01-25

In this paper we study various cosmological solutions for a D3/D7 system directly from M-theory with fluxes and M2-branes. In M-theory, these solutions exist only if we incorporate higher derivative corrections from the curvatures as well as G-fluxes. We take these corrections into account and study a number of toy cosmologies, including one with a novel background for the D3/D7 system whose supergravity solution can be completely determined. Our new background preserves all the good properties of the original model and opens up avenues to investigate cosmological effects from wrapped branes and brane-antibrane annihilation, to name a few. We alsomore » discuss in some detail semilocal defects with higher global symmetries, for example exceptional ones, that occur in a slightly different regime of our D3/D7 model. We show that the D3/D7 system does have the required ingredients to realize these configurations as non-topological solitons of the theory. These constructions also allow us to give a physical meaning to the existence of certain underlying homogeneous quaternionic Kahler manifolds.« less

New black holes in D =5 minimal gauged supergravity: Deformed boundaries and frozen horizons

NASA Astrophysics Data System (ADS)

Blázquez-Salcedo, Jose Luis; Kunz, Jutta; Navarro-Lérida, Francisco; Radu, Eugen

2018-04-01

A new class of black hole solutions of the five-dimensional minimal gauged supergravity is presented. They are characterized by the mass, the electric charge, two equal magnitude angular momenta and the magnitude of the magnetic potential at infinity. These black holes possess a horizon of spherical topology; however, both the horizon and the sphere at infinity can be arbitrarily squashed, with nonextremal solutions interpolating between black strings and black branes. A particular set of extremal configurations corresponds to a new one-parameter family of supersymmetric black holes. While their conserved charges are determined by the squashing of the sphere at infinity, these supersymmetric solutions possess the same horizon geometry.

Generalizations of holographic renormalization group flows

NASA Astrophysics Data System (ADS)

Suh, Minwoo

The AdS/CFT correspondence conjectures the duality between type IIB supergravity on AdS5 × S5 and N = 4 super Yang-Mills theory. Mass deformations of N = 4 super Yang-Mills theory drive renormalization group (RG) flows. Holographic RG flows are described by domain wall solutions interpolating between AdS5 geometries at critical points of N = 8 gauged supergravity in five dimensions. In this thesis we study two directions of generalizations of holographic RG flows. First, motivated by the Janus solutions, we study holographic RG flows with dilaton and axion fields. To be specific, we consider the SU (3)-invariant flow with dilaton and axion fields, and discover the known supersymmetric Janus solution in five dimensions. Then, by employing the lift ansatz, we uplift the supersymmetric Janus solution of the SU(3)-invariant truncation with dilaton and axion fields to a solution of type IIB supergravity. We identify the uplifted solution to be one of the known supersymmetric Janus solution in type IIB supergravity. Furthermore, we consider the SU(2) × U(1)-invariant N = 2 and N = 1 supersymmetric flows with dilaton and axion fields. Second, motivated by the development in AdS/CMT, we study holographic RG flows with gauge fields. We consider the SU(3)-invariant flow with electric potentials or magnetic fields, and find first-order systems of flow equations for each case.

Jordan frame supergravity and inflation in the NMSSM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferrara, Sergio; INFN - Laboratori Nazionali di Frascati, Via Enrico Fermi 40, 00044 Frascati; Kallosh, Renata

2010-08-15

We present a complete explicit N=1, d=4 supergravity action in an arbitrary Jordan frame with nonminimal scalar-curvature coupling of the form {Phi}(z,z)R. The action is derived by suitably gauge fixing the superconformal action. The theory has a modified Kaehler geometry, and it exhibits a significant dependence on the frame function {Phi}(z,z) and its derivatives over scalars, in the bosonic as well as in the fermionic part of the action. Under certain simple conditions, the scalar kinetic terms in the Jordan frame have a canonical form. We consider an embedding of the next-to-minimal supersymmetric standard model (NMSSM) gauge theory into supergravity,more » clarifying the Higgs inflation model recently proposed by Einhorn and Jones. We find that the conditions for canonical kinetic terms are satisfied for the NMSSM scalars in the Jordan frame, which leads to a simple action. However, we find that the gauge singlet field experiences a strong tachyonic instability during inflation in this model. Thus, a modification of the model is required to support the Higgs-type inflation.« less

An analytic superfield formalism for tree superamplitudes in D=10 and D=11

NASA Astrophysics Data System (ADS)

Bandos, Igor

2018-05-01

Tree amplitudes of 10D supersymmetric Yang-Mills theory (SYM) and 11D supergravity (SUGRA) are collected in multi-particle counterparts of analytic on-shell superfields. These have essentially the same form as their chiral 4D counterparts describing N=4 SYM and N=8 SUGRA, but with components dependent on a different set of bosonic variables. These are the D=10 and D=11 spinor helicity variables, the set of which includes the spinor frame variable (Lorentz harmonics) and a scalar density, and generalized homogeneous coordinates of the coset SO(D-2)/SO(D-4)⊗ U(1) (internal harmonics). We present an especially convenient parametrization of the spinor harmonics (Lorentz covariant gauge fixed with the use of an auxiliary gauge symmetry) and use this to find (a gauge fixed version of) the 3-point tree superamplitudes of 10D SYM and 11D SUGRA which generalize the 4 dimensional anti-MHV superamplitudes.

Five-Dimensional Gauged Supergravity with Higher Derivatives

NASA Astrophysics Data System (ADS)

Hanaki, Kentaro

This thesis summarizes the recent developments on the study of five-dimensional gauged supergravity with higher derivative terms, emphasizing in particular the application to understanding the hydrodynamic properties of gauge theory plasma via the AdS/CFT correspondence. We first review how the ungauged and gauged five-dimensional supergravity actions with higher derivative terms can be constructed using the off-shell superconformal formalism. Then we relate the gauged supergravity to four-dimensional gauge theory using the AdS/CFT correspondence and extract the physical quantities associated with gauge theory plasma from the dual classical supergravity computations. We put a particular emphasis on the discussion of the conjectured lower bound for the shear viscosity over entropy density ratio proposed by Kovtun, Son and Starinets, and discuss how higher derivative terms in supergravity and the introduction of chemical potential for the R-charge affect this bound.

Integrable scalar cosmologies. II. Can they fit into Gauged Extended Supergravity or be encoded in N=1 superpotentials?

NASA Astrophysics Data System (ADS)

Fré, P.; Sorin, A. S.; Trigiante, M.

2014-04-01

The question whether the integrable one-field cosmologies classified in a previous paper by Fré, Sagnotti and Sorin can be embedded as consistent one-field truncations into Extended Gauged Supergravity or in N=1 supergravity gauged by a superpotential without the use of D-terms is addressed in this paper. The answer is that such an embedding is very difficult and rare but not impossible. Indeed, we were able to find two examples of integrable models embedded in supergravity in this way. Both examples are fitted into N=1 supergravity by means of a very specific and interesting choice of the superpotential W(z). The question whether there are examples of such an embedding in Extended Gauged Supergravity remains open. In the present paper, relying on the embedding tensor formalism we classified all gaugings of the N=2 STU model, confirming, in the absence on hypermultiplets, the uniqueness of the stable de Sitter vacuum found several years ago by Fré, Trigiante and Van Proeyen and excluding the embedding of any integrable cosmological model. A detailed analysis of the space of exact solutions of the first supergravity-embedded integrable cosmological model revealed several new features worth an in-depth consideration. When the scalar potential has an extremum at a negative value, the Universe necessarily collapses into a Big Crunch notwithstanding its spatial flatness. The causal structure of these Universes is quite different from that of the closed, positive curved, Universe: indeed, in this case the particle and event horizons do not coincide and develop complicated patterns. The cosmological consequences of this unexpected mechanism deserve careful consideration. The Cartan fieldshi associated with the Cartan generators of the Lie algebra G, whose number equals the rank r of G/H. For instance, in models associated with toroidal or orbifold compactifications, fields of this type are generically interpreted as radii of the underlying multi-tori. The axion fieldsbI associated with the roots of the Lie algebra G. The kinetic terms of Cartan scalars have the canonical form ∑ir α/i22 ∂μhi∂μ hi, up to constant coefficients, while for the axion scalars entering solvable coset representatives, the αi2 factors leave way to exponential functions exp[βihi] of Cartan fields. The scalar potentials of Gauged Supergravity are polynomial functions of the coset representatives, so that after the truncation to Cartan sectors, setting the axions to constant values, one is led naturally to combinations of exponentials of the type encountered in [1]. Yet the devil lies in the details, since the integrable potentials do result from exponential functions exp[βh], but with rigidly fixed ratios between the βi entering the exponents and the αi entering the kinetic terms. The candidate potentials are displayed in Tables 1 and 2 following the notations and the nomenclature of [1]. As a result, the possible role of integrable potentials in Gauged Supergravity theories is not evident a priori, and actually, the required ratios are quite difficult to be obtained. Notwithstanding these difficulties we were able to identify a pair of examples, showing that although rare, supergravity integrable cosmological models based on G/H scalar manifolds

A universal counting of black hole microstates in AdS4

NASA Astrophysics Data System (ADS)

Azzurli, Francesco; Bobev, Nikolay; Crichigno, P. Marcos; Min, Vincent S.; Zaffaroni, Alberto

2018-02-01

Many three-dimensional N=2 SCFTs admit a universal partial topological twist when placed on hyperbolic Riemann surfaces. We exploit this fact to derive a universal formula which relates the planar limit of the topologically twisted index of these SCFTs and their three-sphere partition function. We then utilize this to account for the entropy of a large class of supersymmetric asymptotically AdS4 magnetically charged black holes in M-theory and massive type IIA string theory. In this context we also discuss novel AdS2 solutions of eleven-dimensional supergravity which describe the near horizon region of large new families of supersymmetric black holes arising from M2-branes wrapping Riemann surfaces.

Progenitors of Core-Collapse Supernovae

NASA Astrophysics Data System (ADS)

Hirschi, R.; Arnett, D.; Cristini, A.; Georgy, C.; Meakin, C.; Walkington, I.

2017-02-01

Massive stars have a strong impact on their surroundings, in particular when they produce a core-collapse supernova at the end of their evolution. In these proceedings, we review the general evolution of massive stars and their properties at collapse as well as the transition between massive and intermediate-mass stars. We also summarise the effects of metallicity and rotation. We then discuss some of the major uncertainties in the modelling of massive stars, with a particular emphasis on the treatment of convection in 1D stellar evolution codes. Finally, we present new 3D hydrodynamic simulations of convection in carbon burning and list key points to take from 3D hydrodynamic studies for the development of new prescriptions for convective boundary mixing in 1D stellar evolution codes.

Elliptic genera and 3d gravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benjamin, Nathan; Cheng, Miranda C. N.; Kachru, Shamit

Here, we describe general constraints on the elliptic genus of a 2d supersymmetric conformal field theory which has a gravity dual with large radius in Planck units. We give examples of theories which do and do not satisfy the bounds we derive, by describing the elliptic genera of symmetric product orbifolds of K 3, product manifolds, certain simple families of Calabi–Yau hypersurfaces, and symmetric products of the “Monster CFT”. We discuss the distinction between theories with supergravity duals and those whose duals have strings at the scale set by the AdS curvature. Under natural assumptions, we attempt to quantify themore » fraction of (2,2) supersymmetric conformal theories which admit a weakly curved gravity description, at large central charge.« less

Elliptic genera and 3d gravity

DOE PAGES

Benjamin, Nathan; Cheng, Miranda C. N.; Kachru, Shamit; ...

2016-03-30

Here, we describe general constraints on the elliptic genus of a 2d supersymmetric conformal field theory which has a gravity dual with large radius in Planck units. We give examples of theories which do and do not satisfy the bounds we derive, by describing the elliptic genera of symmetric product orbifolds of K 3, product manifolds, certain simple families of Calabi–Yau hypersurfaces, and symmetric products of the “Monster CFT”. We discuss the distinction between theories with supergravity duals and those whose duals have strings at the scale set by the AdS curvature. Under natural assumptions, we attempt to quantify themore » fraction of (2,2) supersymmetric conformal theories which admit a weakly curved gravity description, at large central charge.« less

IIB duals of D = 3 {N} = 4 circular quivers

NASA Astrophysics Data System (ADS)

Assel, Benjamin; Bachas, Costas; Estes, John; Gomis, Jaume

2012-12-01

We construct the type-IIB AdS4 ⋉ K supergravity solutions which are dual to the three-dimensional {N} = 4 superconformal field theories that arise as infrared fixed points of circular-quiver gauge theories. These superconformal field theories are labeled by a triple ( {ρ, hat{ρ},L} ) subject to constraints, where ρ and hat{ρ} are two partitions of a number N, and L is a positive integer. We show that in the limit of large L the localized five- branes in our solutions are effectively smeared, and these type-IIB solutions are dual to the near-horizon geometry of M-theory M2-branes at a {{{{{{C}}^4}}} / {{( {{Z_k}× {Z_{widehat{k}}}} )}} .} orbifold singularity. Our IIB solutions resolve the singularity into localized five-brane throats, without breaking the conformal symmetry. The constraints satisfied by the triple ( {ρ, hat{ρ},L} ) , together with the enhanced non-abelian flavour symmetries of the superconformal field theories are precisely reproduced by the type-IIB supergravity solutions. As a bonus, we uncover a novel type of "orbifold equivalence" between different quantum field theories and provide quantitative evidence for this equivalence.

Cosmology with orthogonal nilpotent superfields

NASA Astrophysics Data System (ADS)

Ferrara, Sergio; Kallosh, Renata; Thaler, Jesse

2016-02-01

We study the application of a supersymmetric model with two constrained supermultiplets to inflationary cosmology. The first superfield S is a stabilizer chiral superfield satisfying a nilpotency condition of degree 2, S2=0 . The second superfield Φ is the inflaton chiral superfield, which can be combined into a real superfield B ≡1/2 i (Φ -Φ ¯ ) . The real superfield B is orthogonal to S , S B =0 , and satisfies a nilpotency condition of degree 3, B3=0 . We show that these constraints remove from the spectrum the complex scalar sgoldstino, the real scalar inflaton partner (i.e. the "sinflaton"), and the fermionic inflatino. The corresponding supergravity model with de Sitter vacua describes a graviton, a massive gravitino, and one real scalar inflaton, with both the goldstino and inflatino being absent in unitary gauge. We also discuss relaxed superfield constraints where S2=0 and S Φ ¯ is chiral, which removes the sgoldstino and inflatino, but leaves the sinflaton in the spectrum. The cosmological model building in both of these inflatino-less models offers some advantages over existing constructions.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arnowitt, R.; Nath, P.

A survey is given of supersymmetry and supergravity and their phenomenology. Some of the topics discussed are the basic ideas of global supersymmetry, the minimal supersymmetric Standard Model (MSSM) and its phenomenology, the basic ideas of local supersymmetry (supergravity), grand unification, supersymmetry breaking in supergravity grand unified models, radiative breaking of SU(2) {times} U(1), proton decay, cosmological constraints, and predictions of supergravity grand unified models. While the number of detailed derivations are necessarily limited, a sufficient number of results are given so that a reader can get a working knowledge of this field.

Off-shell supergravity in five dimensions and supersymmetric brane world scenarios

NASA Astrophysics Data System (ADS)

Zucker, M.

2003-09-01

We review the construction of off-shell Poincaré supergravity in five dimensions. We describe in detail the minimal multiplet, which is the basic building block, containing the propagating fields of supergravity. All matter multiplets containing (8 + 8) components, being the smallest matter multiplets in five dimensions, are constructed. Using these multiplets the complete tensor calculus for supergravity is developed. As expected it turns out, that there exist three distinct minimal (i.e. containing (48 + 48) field components) off-shell supergravities. The lagrangians for these theories and their gauged variants are given explicitly. These results are used in the second part to develop a tensor calculus on the orbifold . Gauged supergravity on the orbifold with additional cosmological constants at the fixpoints, is constructed. This generalizes the work of Randall-Sundrum to local supersymmetry. The developed tensor calculus is used to extend this model to include matter located at the fixpoints. Chiral and super Yang-Mills multiplets at the fixpoints are considered.

Fayet-Iliopoulos terms in supergravity and D-term inflation

NASA Astrophysics Data System (ADS)

Antoniadis, I.; Chatrabhuti, A.; Isono, H.; Knoops, R.

2018-05-01

We analyse the consequences of a new gauge invariant Fayet-Iliopoulos (FI) term proposed recently to a class of inflation models driven by supersymmetry breaking with the inflaton being the superpartner of the goldstino. We first show that charged matter fields can be consistently added with the new term, as well as the standard FI term in supergravity in a Kähler frame where the U(1) is not an R-symmetry. We then show that the slow-roll conditions can be easily satisfied with inflation driven by a D-term depending on the two FI parameters. Inflation starts at initial conditions around the maximum of the potential where the U(1) symmetry is restored and stops when the inflaton rolls down to the minimum describing the present phase of our Universe. The resulting tensor-to-scalar ratio of primordial perturbations can be even at observable values in the presence of higher order terms in the Kähler potential.

Aspects of defects in 3d-3d correspondence

DOE PAGES

Gang, Dongmin; Kim, Nakwoo; Romo, Mauricio; ...

2016-10-12

In this paper we study supersymmetric co-dimension 2 and 4 defects in the compactification of the 6d (2, 0) theory of type A N-1 on a 3-manifold M . The so-called 3d-3d correspondence is a relation between complexified Chern-Simons theory (with gauge group SL(N,C) ) on M and a 3d N=2 theory T N [M ]. We study this correspondence in the presence of supersymmetric defects, which are knots/links inside the 3-manifold. Our study employs a number of different methods: state-integral models for complex Chern-Simons theory, cluster algebra techniques, domain wall theory T [SU(N )], 5d N=2 SYM, and alsomore » supergravity analysis through holography. These methods are complementary and we find agreement between them. In some cases the results lead to highly non-trivial predictions on the partition function. Our discussion includes a general expression for the cluster partition function, which can be used to compute in the presence of maximal and certain class of non-maximal punctures when N > 2. We also highlight the non-Abelian description of the 3d N=2 T N [M ] theory with defect included, when such a description is available. This paper is a companion to our shorter paper, which summarizes our main results.« less

Modulus D-term inflation

NASA Astrophysics Data System (ADS)

Kadota, Kenji; Kobayashi, Tatsuo; Saga, Ikumi; Sumita, Keigo

2018-04-01

We propose a new model of single-field D-term inflation in supergravity, where the inflation is driven by a single modulus field which transforms non-linearly under the U(1) gauge symmetry. One of the notable features of our modulus D-term inflation scenario is that the global U(1) remains unbroken in the vacuum and hence our model is not plagued by the cosmic string problem which can exclude most of the conventional D-term inflation models proposed so far due to the CMB observations.

D-term inflation, cosmic strings, and consistency with cosmic microwave background measurements.

PubMed

Rocher, Jonathan; Sakellariadou, Mairi

2005-01-14

Standard D-term inflation is studied in the framework of supergravity. D-term inflation produces cosmic strings; however, it can still be compatible with cosmic microwave background (CMB) measurements without invoking any new physics. The cosmic strings contribution to the CMB data is not constant, nor dominant, contrary to some previous results. Using current CMB measurements, the free parameters (gauge and superpotential couplings, as well as the Fayet-Iliopoulos term) of D-term inflation are constrained.

Five-dimensional Yang-Mills-Einstein supergravity on orbifold spacetimes: From phenomenology to M -theory

NASA Astrophysics Data System (ADS)

McReynolds, Sean

Five-dimensional N = 2 Yang-Mills-Einstein supergravity and its couplings to hyper and tensor multiplets are considered on an orbifold spacetime of the form M4 x S1/Gamma, where Gamma is a discrete group. As is well known in such cases, supersymmetry is broken to N = 1 on the orbifold fixed planes, and chiral 4D theories can be obtained from bulk hypermultiplets (or from the coupling of fixed-plane supported fields). Five-dimensional gauge symmetries are broken by boundary conditions for the fields, which are equivalent to some set of Gamma-parity assignments in the orbifold theory, allowing for arbitrary rank reduction. Furthermore, Wilson lines looping from one boundary to the other can break bulk gauge groups, or give rise to vacuum expectation values for scalars on the boundaries, which can result in spontaneous breaking of boundary gauge groups. The broken gauge symmetries do not survive as global symmetries of the low energy theories below the compactification scale due to 4 D minimal couplings to gauge fields. Axionic fields are a generic feature, just as in any compactification of M-theory (or string theory for that matter), and we exhibit the form of this field and its role as the QCD axion, capable of resolving the strong CP problem. The main motivation for the orbifold theories here is taken to be orbifold-GUTS, wherein a unified gauge group is sought in higher dimensions while allowing the orbifold reduction to handle problems such as rapid proton decay, exotic matter, mass hierarchies, etc. To that end, we discuss the allowable minimal SU(5), SO(10) and E6 GUT theories with all fields living in five dimensions. It is argued that, within the class of homogeneous quaternionic scalar manifolds characterizing the hypermultiplet couplings in 5D, supergravity admits a restricted set of theories that yield minimal phenomenological field content. In addition, non-compact gaugings are a novel feature of supergravity theories, and in particular we consider the example of an SU(5,1) YMESGT in which all of the fields of the theory are connected by local (susy and gauge) transformations that are symmetries of the Lagrangian. Such non-compact gaugings allow a novel type of gauge-Higgs unification in higher dimensions. The possibility of boundary-localized fields is considered only via anomaly arguments. (Abstract shortened by UMI.)

Inconsistency of topologically massive hypergravity

NASA Technical Reports Server (NTRS)

Aragone, C.; Deser, S.

1985-01-01

The coupled topologically massive spin-5/2 gravity system in D = 3 dimensions whose kinematics represents dynamical propagating gauge invariant massive spin-5/2 and spin-2 excitations, is shown to be inconsistent, or equivalently, not locally hypersymmetric. In contrast to D = 4, the local constraints on the system arising from failure of the fermionic Bianchi identities do not involve the 'highest spin' components of the field, but rather the auxiliary spinor required to construct a consistent massive model.

Euclidean supergravity

NASA Astrophysics Data System (ADS)

de Wit, Bernard; Reys, Valentin

2017-12-01

Supergravity with eight supercharges in a four-dimensional Euclidean space is constructed at the full non-linear level by performing an off-shell time-like reduction of five-dimensional supergravity. The resulting four-dimensional theory is realized off-shell with the Weyl, vector and tensor supermultiplets and a corresponding multiplet calculus. Hypermultiplets are included as well, but they are themselves only realized with on-shell supersymmetry. We also briefly discuss the non-linear supermultiplet. The off-shell reduction leads to a full understanding of the Euclidean theory. A complete multiplet calculus is presented along the lines of the Minkowskian theory. Unlike in Minkowski space, chiral and anti-chiral multiplets are real and supersymmetric actions are generally unbounded from below. Precisely as in the Minkowski case, where one has different formulations of Poincaré supergravity upon introducing different compensating supermultiplets, one can also obtain different versions of Euclidean supergravity.

Hidden symmetries and Lie algebra structures from geometric and supergravity Killing spinors

NASA Astrophysics Data System (ADS)

Açık, Özgür; Ertem, Ümit

2016-08-01

We consider geometric and supergravity Killing spinors and the spinor bilinears constructed out of them. The spinor bilinears of geometric Killing spinors correspond to the antisymmetric generalizations of Killing vector fields which are called Killing-Yano forms. They constitute a Lie superalgebra structure in constant curvature spacetimes. We show that the Dirac currents of geometric Killing spinors satisfy a Lie algebra structure up to a condition on 2-form spinor bilinears. We propose that the spinor bilinears of supergravity Killing spinors give way to different generalizations of Killing vector fields to higher degree forms. It is also shown that those supergravity Killing forms constitute a Lie algebra structure in six- and ten-dimensional cases. For five- and eleven-dimensional cases, the Lie algebra structure depends on an extra condition on supergravity Killing forms.

Generalizing the bms3 and 2D-conformal algebras by expanding the Virasoro algebra

NASA Astrophysics Data System (ADS)

Caroca, Ricardo; Concha, Patrick; Rodríguez, Evelyn; Salgado-Rebolledo, Patricio

2018-03-01

By means of the Lie algebra expansion method, the centrally extended conformal algebra in two dimensions and the bms3 algebra are obtained from the Virasoro algebra. We extend this result to construct new families of expanded Virasoro algebras that turn out to be infinite-dimensional lifts of the so-called Bk, Ck and Dk algebras recently introduced in the literature in the context of (super)gravity. We also show how some of these new infinite-dimensional symmetries can be obtained from expanded Kač-Moody algebras using modified Sugawara constructions. Applications in the context of three-dimensional gravity are briefly discussed.

Complexity growth in minimal massive 3D gravity

NASA Astrophysics Data System (ADS)

Qaemmaqami, Mohammad M.

2018-01-01

We study the complexity growth by using "complexity =action " (CA) proposal in the minimal massive 3D gravity (MMG) model which is proposed for resolving the bulk-boundary clash problem of topologically massive gravity (TMG). We observe that the rate of the complexity growth for Banados-Teitelboim-Zanelli (BTZ) black hole saturates the proposed bound by physical mass of the BTZ black hole in the MMG model, when the angular momentum parameter and the inner horizon of black hole goes to zero.

Scattering amplitudes in $$\\mathcal{N}=2 $$ Maxwell-Einstein and Yang-Mills/Einstein supergravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiodaroli, Marco; Gunaydin, Murat; Johansson, Henrik

We expose a double-copy structure in the scattering amplitudes of the generic Jordan family of N = 2 Maxwell-Einstein and Yang-Mills/Einstein supergravity theories in four and five dimensions. The Maxwell-Einstein supergravity amplitudes are obtained through the color/kinematics duality as a product of two gauge-theory factors; one originating from pure N = 2 super-Yang-Mills theory and the other from the dimensional reduction of a bosonic higher-dimensional pure Yang-Mills theory. We identify a specific symplectic frame in four dimensions for which the on-shell fields and amplitudes from the double-copy construction can be identified with the ones obtained from the supergravity Lagrangian andmore » Feynman-rule computations. The Yang-Mills/Einstein supergravity theories are obtained by gauging a compact subgroup of the isometry group of their Maxwell-Einstein counterparts. For the generic Jordan family this process is identified with the introduction of cubic scalar couplings on the bosonic gauge-theory side, which through the double copy are responsible for the non-abelian vector interactions in the supergravity theory. As a demonstration of the power of this structure, we present explicit computations at treelevel and one loop. Lastly, the double-copy construction allows us to obtain compact expressions for the supergravity superamplitudes, which are naturally organized as polynomials in the gauge coupling constant.« less

Scattering amplitudes in $$\\mathcal{N}=2 $$ Maxwell-Einstein and Yang-Mills/Einstein supergravity

DOE PAGES

Chiodaroli, Marco; Gunaydin, Murat; Johansson, Henrik; ...

2015-01-15

We expose a double-copy structure in the scattering amplitudes of the generic Jordan family of N = 2 Maxwell-Einstein and Yang-Mills/Einstein supergravity theories in four and five dimensions. The Maxwell-Einstein supergravity amplitudes are obtained through the color/kinematics duality as a product of two gauge-theory factors; one originating from pure N = 2 super-Yang-Mills theory and the other from the dimensional reduction of a bosonic higher-dimensional pure Yang-Mills theory. We identify a specific symplectic frame in four dimensions for which the on-shell fields and amplitudes from the double-copy construction can be identified with the ones obtained from the supergravity Lagrangian andmore » Feynman-rule computations. The Yang-Mills/Einstein supergravity theories are obtained by gauging a compact subgroup of the isometry group of their Maxwell-Einstein counterparts. For the generic Jordan family this process is identified with the introduction of cubic scalar couplings on the bosonic gauge-theory side, which through the double copy are responsible for the non-abelian vector interactions in the supergravity theory. As a demonstration of the power of this structure, we present explicit computations at treelevel and one loop. Lastly, the double-copy construction allows us to obtain compact expressions for the supergravity superamplitudes, which are naturally organized as polynomials in the gauge coupling constant.« less

From osp(1|32)⊕osp(1|32) to the M-theory superalgebra: a contraction procedure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fernández, J. J., E-mail: julio.j.fernandez@hotmail.es; Izquierdo, J. M., E-mail: izquierd@fta.uva.es; Olmo, M. A. del, E-mail: olmo@fta.uva.es

We show the impossibility to obtain the D’auria–Fré-type superalgebras that allow for an underlying gauge theoretical structure of D = 11 supergravity from the superalgebra osp(1|32)⊕osp(1|32)−, by means of aWeimar-Woods contraction.

Holography, black holes and condensed matter physics

NASA Astrophysics Data System (ADS)

Gentle, Simon Adam

In this thesis we employ holographic techniques to explore strongly-coupled quantum field theories at non-zero temperature and density. First we consider a state dual to a charged black hole with planar horizon and compute retarded Green's functions for conserved currents in the shear channel. We demonstrate the intricate motion of their poles and stress the importance of the residues at the poles beyond the hydrodynamic regime. We then explore the collective excitations of holographic quantum liquids arising on D3/D5 and D3/D7 brane intersections as a function of temperature and magnetic field in the probe limit. We observe a crossover from hydrodynamic charge diffusion to a sound mode similar to the zero sound mode in the collisionless regime of a Landau Fermi liquid. The location of this crossover is approximately independent of the magnetic field. The sound mode has a gap proportional to the magnetic field, leading to strong suppression of spectral weight for intermediate frequencies and sufficiently large magnetic fields. In the second part we explore the solution space of AdS gravity in the hope of learning general lessons about such theories. First we study charged scalar solitons in global AdS4. These solutions have a rich phase space and exhibit critical behaviour as a function of the scalar charge and scalar boundary conditions. We demonstrate how the planar limit of global solitons coincides generically with the zero-temperature limit of black branes with charged scalar hair. We exhibit these features in both phenomenological models and consistent truncations of eleven-dimensional supergravity. We then discover new branches of hairy black brane in SO(6) gauged supergravity. Despite the imbalance provided by three chemical potentials conjugate to the three R-charges, there is always at least one branch with charged scalar hair, emerging at a temperature where the normal phase is locally thermodynamically stable.

Chaotic inflation from nonlinear sigma models in supergravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hellerman, Simeon; Kehayias, John; Yanagida, Tsutomu T.

2015-02-11

We present a common solution to the puzzles of the light Higgs or quark masses and the need for a shift symmetry and large field values in high scale chaotic inflation. One way to protect, for example, the Higgs from a large supersymmetric mass term is if it is the Nambu–Goldstone boson (NGB) of a nonlinear sigma model. However, it is well known that nonlinear sigma models (NLSMs) with nontrivial Kähler transformations are problematic to couple to supergravity. An additional field is necessary to make theKähler potential of the NLSM invariant in supergravity. This field must have a shift symmetrymore » — making it a candidate for the inflaton (or axion). We give an explicit example of such a model for the coset space SU(3)/SU(2) × U(1), with the Higgs as the NGB, including breaking the inflaton’s shift symmetry and producing a chaotic inflation potential. This construction can also be applied to other models, such as one based on E₇/SO(10) × U(1) × U(1) which incorporates the first two generations of (light) quarks as the Nambu–Goldstone multiplets, and has an axion in addition to the inflaton. Along the way we clarify and connect previous work on understanding NLSMs in supergravity and the origin of the extra field (which is the inflaton here), including a connection to Witten–Bagger quantization. This framework has wide applications to model building; a light particle from a NLSM requires, in supergravity, exactly the structure for chaotic inflaton or an axion« less

Dyonic AdS black holes in maximal gauged supergravity

NASA Astrophysics Data System (ADS)

Chow, David D. K.; Compère, Geoffrey

2014-03-01

We present two new classes of dyonic anti-de Sitter black hole solutions of four-dimensional maximal N =8, SO(8) gauged supergravity. They are (1) static black holes of N=2, U(1)4 gauged supergravity with four electric and four magnetic charges, with spherical, planar or hyperbolic horizons; and (2) rotating black holes of N =2, U(1)2 gauged supergravity with two electric and two magnetic charges. We study their thermodynamics, and point out that the formulation of a consistent thermodynamics for dyonic anti-de Sitter black holes is dependent on the existence of boundary conditions for the gauge fields. We identify several distinct classes of boundary conditions for gauge fields in U(1)4 supergravity. We study a general family of metrics containing the rotating solutions, and find Killing-Yano tensors with torsion in two conformal frames, which underlie separability.

IIB supergravity and the E 6(6) covariant vector-tensor hierarchy

DOE PAGES

Ciceri, Franz; de Wit, Bernard; Varela, Oscar

2015-04-20

IIB supergravity is reformulated with a manifest local USp(8) invariance that makes the embedding of five-dimensional maximal supergravities transparent. In this formulation the ten-dimensional theory exhibits all the 27 one-form fields and 22 of the 27 two-form fields that are required by the vector-tensor hierarchy of the five-dimensional theory. The missing 5 two-form fields must transform in the same representation as a descendant of the ten-dimensional ‘dual graviton’. The invariant E 6(6) symmetric tensor that appears in the vector-tensor hierarchy is reproduced. Generalized vielbeine are derived from the supersymmetry transformations of the vector fields, as well as consistent expressions formore » the USp(8) covariant fermion fields. Implications are further discussed for the consistency of the truncation of IIB supergravity compactified on the five-sphere to maximal gauged supergravity in five space-time dimensions with an SO(6) gauge group.« less

New variables for classical and quantum gravity in all dimensions: I. Hamiltonian analysis

NASA Astrophysics Data System (ADS)

Bodendorfer, N.; Thiemann, T.; Thurn, A.

2013-02-01

Loop quantum gravity (LQG) relies heavily on a connection formulation of general relativity such that (1) the connection Poisson commutes with itself and (2) the corresponding gauge group is compact. This can be achieved starting from the Palatini or Holst action when imposing the time gauge. Unfortunately, this method is restricted to D + 1 = 4 spacetime dimensions. However, interesting string theories and supergravity theories require higher dimensions and it would therefore be desirable to have higher dimensional supergravity loop quantizations at one’s disposal in order to compare these approaches. In this series of papers we take first steps toward this goal. The present first paper develops a classical canonical platform for a higher dimensional connection formulation of the purely gravitational sector. The new ingredient is a different extension of the ADM phase space than the one used in LQG which does not require the time gauge and which generalizes to any dimension D > 1. The result is a Yang-Mills theory phase space subject to Gauß, spatial diffeomorphism and Hamiltonian constraint as well as one additional constraint, called the simplicity constraint. The structure group can be chosen to be SO(1, D) or SO(D + 1) and the latter choice is preferred for purposes of quantization.

Separation of Non-metallic Inclusions from a Fe-Al-O Melt Using a Super-Gravity Field

NASA Astrophysics Data System (ADS)

Song, Gaoyang; Song, Bo; Guo, Zhancheng; Yang, Yuhou; Song, Mingming

2018-02-01

An innovative method for separating non-metallic inclusions from a high temperature melt using super gravity was systematically investigated. To explore the separation behavior of inclusion particles with densities less than that of metal liquid under a super-gravity field, a Fe-Al-O melt containing Al2O3 particles was treated with different gravity coefficients. Al2O3 particles migrated rapidly towards the reverse direction of the super gravity and gathered in the upper region of the sample. It was hard to find any inclusion particles with sizes greater than 2 μm in the middle and bottom areas. Additionally, the oxygen content in the middle region of the sample could be reduced to 0.0022 mass pct and the maximum removal rate of the oxygen content reached 61.4 pct. The convection in the melt along the direction of the super gravity was not generated by the super-gravity field, and the fluid velocity in the molten melt consisted only of the rotating tangential velocity. Moreover, the motion behavior of the Al2O3 particles was approximatively determined by Stokes' law along the direction of super gravity.

Accidental SUSY: enhanced bulk supersymmetry from brane back-reaction

NASA Astrophysics Data System (ADS)

Burgess, C. P.; van Nierop, L.; Parameswaran, S.; Salvio, A.; Williams, M.

2013-02-01

We compute how bulk loops renormalize both bulk and brane effective interactions for codimension-two branes in 6D gauged chiral supergravity, as functions of the brane tension and brane-localized flux. We do so by explicitly integrating out hyper- and gauge-multiplets in 6D gauged chiral supergravity compactified to 4D on a flux-stabilized 2D rugby-ball geometry, specializing the results of a companion paper, arXiv:1210.3753, to the supersymmetric case. While the brane back-reaction generically breaks supersymmetry, we show that the bulk supersymmetry can be preserved if the amount of brane- localized flux is related in a specific BPS-like way to the brane tension, and verify that the loop corrections to the brane curvature vanish in this special case. In these systems it is the brane-bulk couplings that fix the size of the extra dimensions, and we show that in some circumstances the bulk geometry dynamically adjusts to ensure the supersymmetric BPS-like condition is automatically satisfied. We investigate the robustness of this residual supersymmetry to loops of non-supersymmetric matter on the branes, and show that supersymmetry-breaking effects can enter only through effective brane-bulk interactions involving at least two derivatives. We comment on the relevance of this calculation to proposed applications of codimension-two 6D models to solutions of the hierarchy and cosmological constant problems.

Counting supersymmetric branes

NASA Astrophysics Data System (ADS)

Kleinschmidt, Axel

2011-10-01

Maximal supergravity solutions are revisited and classified, with particular emphasis on objects of co-dimension at most two. This class of solutions includes branes whose tension scales with xxxx. We present a group theory derivation of the counting of these objects based on the corresponding tensor hierarchies derived from E 11 and discrete T- and U-duality transformations. This provides a rationale for the wrapping rules that were recently discussed for σ ≤ 3 in the literature and extends them. Explicit supergravity solutions that give rise to co-dimension two branes are constructed and analysed.

A locally supersymmetric SO(10, 2) invariant action for D = 12 supergravity

NASA Astrophysics Data System (ADS)

Castellani, Leonardo

2017-06-01

We present an action for N = 1 supergravity in 10 + 2 dimensions, containing the gauge fields of the OSp(1|64) superalgebra, i.e. one-forms B ( n) with n=1,2,5,6,9,10 antisymmetric D=12 Lorentz indices and a Majorana gravitino ψ. The vielbein and spin connection correspond to B (1) and B (2) respectively. The action is not gauge invariant under the full OSp(1|64) superalgebra, but only under a subalgebra \\tilde{F} (containing the F algebra OSp(1|32)), whose gauge fields are B (2), B (6), B (10) and the Weyl projected Majorana gravitino 1/2(1+{Γ}_{13})ψ . Supersymmetry transformations are therefore generated by a Majorana-Weyl supercharge and, being part of a gauge superalgebra, close off-shell. The action is simply ∫ STr( R 6 Γ) where R is the OSp(1|64) curvature supermatrix two-form, and Γ is a constant supermatrix involving Γ13 and breaking OSp(1|64) to its \\tilde{F} subalgebra. The usual Einstein-Hilbert term is included in the action.

Kicking the rugby ball: perturbations of 6D gauged chiral supergravity

NASA Astrophysics Data System (ADS)

Burgess, C. P.; de Rham, C.; Hoover, D.; Mason, D.; Tolley, A. J.

2007-02-01

We analyse the axially symmetric scalar perturbations of 6D chiral gauged supergravity compactified on the general warped geometries in the presence of two source branes. We find that all of the conical geometries are marginally stable for normalizable perturbations (in disagreement with some recent calculations) and the non-conical ones for regular perturbations, even though none of them are supersymmetric (apart from the trivial Salam Sezgin solution, for which there are no source branes). The marginal direction is the one whose presence is required by the classical scaling property of the field equations, and all other modes have positive squared mass. In the special case of the conical solutions, including (but not restricted to) the unwarped 'rugby-ball' solutions, we find closed-form expressions for the mode functions in terms of Legendre and hypergeometric functions. In so doing we show how to match the asymptotic near-brane form for the solution to the physics of the source branes, and thereby how to physically interpret perturbations which can be singular at the brane positions.

String theory, gauge theory and quantum gravity. Proceedings. Trieste Spring School and Workshop on String Theory, Gauge Theory and Quantum Gravity, Trieste (Italy), 11 - 22 Apr 1994.

NASA Astrophysics Data System (ADS)

1995-04-01

The following topics were dealt with: string theory, gauge theory, quantum gravity, quantum geometry, black hole physics and information loss, second quantisation of the Wilson loop, 2D Yang-Mills theory, topological field theories, equivariant cohomology, superstring theory and fermion masses, supergravity, topological gravity, waves in string cosmology, superstring theories, 4D space-time.

New families of interpolating type IIB backgrounds

NASA Astrophysics Data System (ADS)

Minasian, Ruben; Petrini, Michela; Zaffaroni, Alberto

2010-04-01

We construct new families of interpolating two-parameter solutions of type IIB supergravity. These correspond to D3-D5 systems on non-compact six-dimensional manifolds which are mathbb{T}2 fibrations over Eguchi-Hanson and multi-center Taub-NUT spaces, respectively. One end of the interpolation corresponds to a solution with only D5 branes and vanishing NS three-form flux. A topology changing transition occurs at the other end, where the internal space becomes a direct product of the four-dimensional surface and the two-torus and the complexified NS-RR three-form flux becomes imaginary self-dual. Depending on the choice of the connections on the torus fibre, the interpolating family has either mathcal{N}=2 or mathcal{N}=1 supersymmetry. In the mathcal{N}=2 case it can be shown that the solutions are regular.

Formation and pre-MS Evolution of Massive Stars with Growing Accretion

NASA Astrophysics Data System (ADS)

Maeder, A.; Behrend, R.

2002-10-01

We briefly describe the three existing scenarios for forming massive stars and emphasize that the arguments often used to reject the accretion scenario for massive stars are misleading. It is usually not accounted for the fact that the turbulent pressure associated to large turbulent velocities in clouds necessarily imply relatively high accretion rates for massive stars. We show the basic difference between the formation of low and high mass stars based on the values of the free fall time and of the Kelvin-Helmholtz timescale, and define the concept of birthline for massive stars. Due to D-burning, the radius and location of the birthline in the HR diagram, as well as the lifetimes are very sensitive to the accretion rate dM/dt(accr). If a form dM/dt(accr) propto A(M/Msun)phi is adopted, the observations in the HR diagram and the lifetimes support a value of A approx 10-5 Msun/yr and a value of phi > 1. Remarkably, such a law is consistent with the relation found by Churchwell and Henning et al. between the outflow rates and the luminosities of ultracompact HII regions, if we assume that a fraction 0.15 to 0.3 of the global inflow is accreted. The above relation implies high dM/dt(accr) approx 10-3 Msun/yr for the most massive stars. The physical possibility of such high dM/dt(accr) is supported by current numerical models. Finally, we give simple analytical arguments in favour of the growth of dM/dt(accr) with the already accreted mass. We also suggest that due to Bondi-Hoyle accretion, the formation of binary stars is largely favoured among massive stars in the accretion scenario.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baguet, A.; Pope, Christopher N.; Samtleben, H.

We prove an old conjecture by Duff, Nilsson, Pope and Warner asserting that the NSNS sector of supergravity (and more general the bosonic string) allows for a consistent Pauli reduction on any d-dimensional group manifold G, keeping the full set of gauge bosons of the G×G isometry group of the bi-invariant metric on G. The main tool of the construction is a particular generalised Scherk–Schwarz reduction ansatz in double field theory which we explicitly construct in terms of the group's Killing vectors. Examples include the consistent reduction from ten dimensions on S3×S3 and on similar product spaces. The construction ismore » another example of globally geometric non-toroidal compactifications inducing non-geometric fluxes.« less

Does the first chaotic inflation model in supergravity provide the best fit to the Planck data?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Linde, Andrei

2015-02-23

I describe the first model of chaotic inflation in supergravity, which was proposed by Goncharov and the present author in 1983. The inflaton potential of this model has a plateau-type behavior V{sub 0}(1−(8/3) e{sup −√6|ϕ|}) at large values of the inflaton field. This model predicts n{sub s}=1−(2/N)≈0.967 and r=(4/(3N{sup 2}))≈4×10{sup −4}, in good agreement with the Planck data. I propose a slight generalization of this model, which allows to describe not only inflation but also dark energy and supersymmetry breaking.

Practical 3-D Beam Pattern Based Channel Modeling for Multi-Polarized Massive MIMO Systems.

PubMed

Aghaeinezhadfirouzja, Saeid; Liu, Hui; Balador, Ali

2018-04-12

In this paper, a practical non-stationary three-dimensional (3-D) channel models for massive multiple-input multiple-output (MIMO) systems, considering beam patterns for different antenna elements, is proposed. The beam patterns using dipole antenna elements with different phase excitation toward the different direction of travels (DoTs) contributes various correlation weights for rays related towards/from the cluster, thus providing different elevation angle of arrivals (EAoAs) and elevation angle of departures (EAoDs) for each antenna element. These include the movements of the user that makes our channel to be a non-stationary model of clusters at the receiver (RX) on both the time and array axes. In addition, their impacts on 3-D massive MIMO channels are investigated via statistical properties including received spatial correlation. Additionally, the impact of elevation/azimuth angles of arrival on received spatial correlation is discussed. Furthermore, experimental validation of the proposed 3-D channel models on azimuth and elevation angles of the polarized antenna are specifically evaluated and compared through simulations. The proposed 3-D generic models are verified using relevant measurement data.

Practical 3-D Beam Pattern Based Channel Modeling for Multi-Polarized Massive MIMO Systems †

PubMed Central

Aghaeinezhadfirouzja, Saeid; Liu, Hui

2018-01-01

In this paper, a practical non-stationary three-dimensional (3-D) channel models for massive multiple-input multiple-output (MIMO) systems, considering beam patterns for different antenna elements, is proposed. The beam patterns using dipole antenna elements with different phase excitation toward the different direction of travels (DoTs) contributes various correlation weights for rays related towards/from the cluster, thus providing different elevation angle of arrivals (EAoAs) and elevation angle of departures (EAoDs) for each antenna element. These include the movements of the user that makes our channel to be a non-stationary model of clusters at the receiver (RX) on both the time and array axes. In addition, their impacts on 3-D massive MIMO channels are investigated via statistical properties including received spatial correlation. Additionally, the impact of elevation/azimuth angles of arrival on received spatial correlation is discussed. Furthermore, experimental validation of the proposed 3-D channel models on azimuth and elevation angles of the polarized antenna are specifically evaluated and compared through simulations. The proposed 3-D generic models are verified using relevant measurement data. PMID:29649177

Precision lattice test of the gauge/gravity duality at large N

DOE PAGES

Berkowitz, Evan; Rinaldi, Enrico; Hanada, Masanori; ...

2016-11-03

We perform a systematic, large-scale lattice simulation of D0-brane quantum mechanics. The large-N and continuum limits of the gauge theory are taken for the first time at various temperatures 0.4≤T≤1.0. As a way to test the gauge/gravity duality conjecture we compute the internal energy of the black hole as a function of the temperature directly from the gauge theory. We obtain a leading behavior that is compatible with the supergravity result E/N 2=7.41T 14/5: the coefficient is estimated to be 7.4±0.5 when the exponent is fixed and stringy corrections are included. This is the first confirmation of the supergravity predictionmore » for the internal energy of a black hole at finite temperature coming directly from the dual gauge theory. As a result, we also constrain stringy corrections to the internal energy.« less

Entanglement entropy of ABJM theory and entropy of topological black hole

NASA Astrophysics Data System (ADS)

Nian, Jun; Zhang, Xinyu

2017-07-01

In this paper we discuss the supersymmetric localization of the 4D N = 2 offshell gauged supergravity on the background of the AdS4 neutral topological black hole, which is the gravity dual of the ABJM theory defined on the boundary {S}^1× H^2 . We compute the large- N expansion of the supergravity partition function. The result gives the black hole entropy with the logarithmic correction, which matches the previous result of the entanglement entropy of the ABJM theory up to some stringy effects. Our result is consistent with the previous on-shell one-loop computation of the logarithmic correction to black hole entropy. It provides an explicit example of the identification of the entanglement entropy of the boundary conformal field theory with the bulk black hole entropy beyond the leading order given by the classical Bekenstein-Hawking formula, which consequently tests the AdS/CFT correspondence at the subleading order.

Scalable Multi-Platform Distribution of Spatial 3d Contents

NASA Astrophysics Data System (ADS)

Klimke, J.; Hagedorn, B.; Döllner, J.

2013-09-01

Virtual 3D city models provide powerful user interfaces for communication of 2D and 3D geoinformation. Providing high quality visualization of massive 3D geoinformation in a scalable, fast, and cost efficient manner is still a challenging task. Especially for mobile and web-based system environments, software and hardware configurations of target systems differ significantly. This makes it hard to provide fast, visually appealing renderings of 3D data throughout a variety of platforms and devices. Current mobile or web-based solutions for 3D visualization usually require raw 3D scene data such as triangle meshes together with textures delivered from server to client, what makes them strongly limited in terms of size and complexity of the models they can handle. In this paper, we introduce a new approach for provisioning of massive, virtual 3D city models on different platforms namely web browsers, smartphones or tablets, by means of an interactive map assembled from artificial oblique image tiles. The key concept is to synthesize such images of a virtual 3D city model by a 3D rendering service in a preprocessing step. This service encapsulates model handling and 3D rendering techniques for high quality visualization of massive 3D models. By generating image tiles using this service, the 3D rendering process is shifted from the client side, which provides major advantages: (a) The complexity of the 3D city model data is decoupled from data transfer complexity (b) the implementation of client applications is simplified significantly as 3D rendering is encapsulated on server side (c) 3D city models can be easily deployed for and used by a large number of concurrent users, leading to a high degree of scalability of the overall approach. All core 3D rendering techniques are performed on a dedicated 3D rendering server, and thin-client applications can be compactly implemented for various devices and platforms.

Supergravity backgrounds for deformations of AdS n × S n supercoset string models

DOE PAGES

Lunin, O.; Roiban, R.; Tseytlin, A. A.

2014-12-11

We considermore » type IIB supergravity backgrounds corresponding to the deformed AdS n × S n × T 10 - 2 n supercoset string models of the type constructed in arXiv:1309.5850[2] which depend on one deformation parameter κ. In AdS 2 × S 2 case we find that the deformed metric can be extended to a full supergravity solution with non-trivial dilaton, RR scalar and RR 5-form strength. The solution depends on a free parameter a that should be chosen as a particular function of κ to correspond to the deformed supercoset model. In AdS 3 × S 3 case the full solution supported by the dilaton, RR scalar and RR 3-form strength exists only in the two special cases, a = 0 and a = 1 . We conjecture that there may be a more general one-parameter solution supported by several RR fields that for particular a = a ( κ ) corresponds to the supercoset model. In the most complicated deformed AdS 5 × S 5 case we were able to find only the expressions for the dilaton and the RR scalar. The full solution is likely to be supported by a combination of the 5-form and 3-form field strengths. We comment on the singularity structure of the resulting metric and exact dilaton field.« less

Supergravity backgrounds for deformations of AdS n × S n supercoset string models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lunin, O.; Roiban, R.; Tseytlin, A. A.

We considermore » type IIB supergravity backgrounds corresponding to the deformed AdS n × S n × T 10 - 2 n supercoset string models of the type constructed in arXiv:1309.5850[2] which depend on one deformation parameter κ. In AdS 2 × S 2 case we find that the deformed metric can be extended to a full supergravity solution with non-trivial dilaton, RR scalar and RR 5-form strength. The solution depends on a free parameter a that should be chosen as a particular function of κ to correspond to the deformed supercoset model. In AdS 3 × S 3 case the full solution supported by the dilaton, RR scalar and RR 3-form strength exists only in the two special cases, a = 0 and a = 1 . We conjecture that there may be a more general one-parameter solution supported by several RR fields that for particular a = a ( κ ) corresponds to the supercoset model. In the most complicated deformed AdS 5 × S 5 case we were able to find only the expressions for the dilaton and the RR scalar. The full solution is likely to be supported by a combination of the 5-form and 3-form field strengths. We comment on the singularity structure of the resulting metric and exact dilaton field.« less

The Circumgalactic Medium in Massive Halos

NASA Astrophysics Data System (ADS)

Chen, Hsiao-Wen

This chapter presents a review of the current state of knowledge on the cool (T ˜ 104 K) halo gas content around massive galaxies at z ≈ 0. 2-2. Over the last decade, significant progress has been made in characterizing the cool circumgalactic gas in massive halos of M h ≈ 1012-14 M⊙ at intermediate redshifts using absorption spectroscopy. Systematic studies of halo gas around massive galaxies beyond the nearby universe are made possible by large spectroscopic samples of galaxies and quasars in public archives. In addition to accurate and precise constraints for the incidence of cool gas in massive halos, detailed characterizations of gas kinematics and chemical compositions around massive quiescent galaxies at z ≈ 0. 5 have also been obtained. Combining all available measurements shows that infalling clouds from external sources are likely the primary source of cool gas detected at

Functional determinants, index theorems, and exact quantum black hole entropy

NASA Astrophysics Data System (ADS)

Murthy, Sameer; Reys, Valentin

2015-12-01

The exact quantum entropy of BPS black holes can be evaluated using localization in supergravity. An important ingredient in this program, that has been lacking so far, is the one-loop effect arising from the quadratic fluctuations of the exact deformation (the QV operator). We compute the fluctuation determinant for vector multiplets and hyper multiplets around Q-invariant off-shell configurations in four-dimensional N=2 supergravity with AdS 2 × S 2 boundary conditions, using the Atiyah-Bott fixed-point index theorem and a subsequent zeta function regularization. Our results extend the large-charge on-shell entropy computations in the literature to a regime of finite charges. Based on our results, we present an exact formula for the quantum entropy of BPS black holes in N=2 supergravity. We explain cancellations concerning 1/8 -BPS black holes in N=8 supergravity that were observed in arXiv:1111.1161. We also make comments about the interpretation of a logarithmic term in the topological string partition function in the low energy supergravity theory.

Topological resolution of gauge theory singularities

NASA Astrophysics Data System (ADS)

Saracco, Fabio; Tomasiello, Alessandro; Torroba, Gonzalo

2013-08-01

Some gauge theories with Coulomb branches exhibit singularities in perturbation theory, which are usually resolved by nonperturbative physics. In string theory this corresponds to the resolution of timelike singularities near the core of orientifold planes by effects from F or M theory. We propose a new mechanism for resolving Coulomb branch singularities in three-dimensional gauge theories, based on Chern-Simons interactions. This is illustrated in a supersymmetric SU(2) Yang-Mills-Chern-Simons theory. We calculate the one-loop corrections to the Coulomb branch of this theory and find a result that interpolates smoothly between the high-energy metric (that would exhibit the singularity) and a regular singularity-free low-energy result. We suggest possible applications to singularity resolution in string theory and speculate a relationship to a similar phenomenon for the orientifold six-plane in massive IIA supergravity.

Kundt solutions of minimal massive 3D gravity

NASA Astrophysics Data System (ADS)

Deger, Nihat Sadik; Sarıoǧlu, Ã.-zgür

2015-11-01

We construct Kundt solutions of minimal massive gravity theory and show that, similar to topologically massive gravity (TMG), most of them are constant scalar invariant (CSI) spacetimes that correspond to deformations of round and warped (A)dS. We also find an explicit non-CSI Kundt solution at the merger point. Finally, we give their algebraic classification with respect to the traceless Ricci tensor (Segre classification) and show that their Segre types match with the types of their counterparts in TMG.

Counting spinning dyons in maximal supergravity: the Hodge-elliptic genus for tori

NASA Astrophysics Data System (ADS)

Benjamin, Nathan; Kachru, Shamit; Tripathy, Arnav

2017-11-01

We consider M-theory compactified on T^4 × T^2 and describe the count of spinning 1/8-BPS states. This builds on the work of Maldacena-Moore-Strominger in the physics literature. It simultaneously provides a refinement of the recent mathematical work of Bryan-Oberdieck-Pandharipande-Yin and Oberdieck-Shen, which studied (non-motivic) reduced Donaldson-Thomas invariants of abelian surfaces and threefolds. As in previous work on K3 × T^2 compactification, we track angular momenta under both the SU(2)_L and SU(2)_R factors in the 5d little group, providing predictions for the relevant motivic curve counts.

Minimal massive 3D gravity

NASA Astrophysics Data System (ADS)

Bergshoeff, Eric; Hohm, Olaf; Merbis, Wout; Routh, Alasdair J.; Townsend, Paul K.

2014-07-01

We present an alternative to topologically massive gravity (TMG) with the same ‘minimal’ bulk properties; i.e. a single local degree of freedom that is realized as a massive graviton in linearization about an anti-de Sitter (AdS) vacuum. However, in contrast to TMG, the new ‘minimal massive gravity’ has both a positive energy graviton and positive central charges for the asymptotic AdS-boundary conformal algebra.

Quantum supergravity, supergravity anomalies and string phenomenology

DOE PAGES

Gaillard, Mary K.

2016-03-15

I discuss the role of quantum effects in the phenomenology of effective supergravity theories from compactification of the weakly coupled heterotic string. An accurate incorporation of these effects requires a regularization procedure that respects local supersymmetry and BRST invariance and that retains information associated with the cut-off scale, which has physical meaning in an effective theory. I briefly outline the Pauli–Villars regularization procedure, describe some applications, and comment on what remains to be done to fully define the effective quantum field theory.

Impacts of supersymmetric higher derivative terms on inflation models in supergravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aoki, Shuntaro; Yamada, Yusuke, E-mail: shun-soccer@akane.waseda.jp, E-mail: yuusuke-yamada@asagi.waseda.jp

2015-07-01

We show the effects of supersymmetric higher derivative terms on inflation models in supergravity. The results show that such terms generically modify the effective kinetic coefficient of the inflaton during inflation if the cut off scale of the higher derivative operators is sufficiently small. In such a case, the η-problem in supergravity does not occur, and we find that the effective potential of the inflaton generically becomes a power type potential with a power smaller than two.

On supersymmetric anti-de Sitter, de Sitter and Minkowski flux backgrounds

NASA Astrophysics Data System (ADS)

Gran, U.; Gutowski, J. B.; Papadopoulos, G.

2018-03-01

We test the robustness of the conditions required for the existence of (supersymmetric) warped flux anti-de Sitter, de Sitter, and Minkowski backgrounds in supergravity theories using as examples suitable foliations of anti-de Sitter spaces. We find that there are supersymmetric de Sitter solutions in supergravity theories including maximally supersymmetric ones in 10- and 11-dimensional supergravities. Moreover, warped flux Minkowski backgrounds can admit Killing spinors which are not Killing on the Minkowski subspace and therefore cannot be put in a factorized form.

THE THREE-DIMENSIONAL EVOLUTION TO CORE COLLAPSE OF A MASSIVE STAR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Couch, Sean M.; Chatzopoulos, Emmanouil; Arnett, W. David

2015-07-20

We present the first three-dimensional (3D) simulation of the final minutes of iron core growth in a massive star, up to and including the point of core gravitational instability and collapse. We capture the development of strong convection driven by violent Si burning in the shell surrounding the iron core. This convective burning builds the iron core to its critical mass and collapse ensues, driven by electron capture and photodisintegration. The non-spherical structure and motion generated by 3D convection is substantial at the point of collapse, with convective speeds of several hundreds of km s{sup −1}. We examine the impactmore » of such physically realistic 3D initial conditions on the core-collapse supernova mechanism using 3D simulations including multispecies neutrino leakage and find that the enhanced post-shock turbulence resulting from 3D progenitor structure aids successful explosions. We conclude that non-spherical progenitor structure should not be ignored, and should have a significant and favorable impact on the likelihood for neutrino-driven explosions. In order to make simulating the 3D collapse of an iron core feasible, we were forced to make approximations to the nuclear network making this effort only a first step toward accurate, self-consistent 3D stellar evolution models of the end states of massive stars.« less

Consistent Pauli reduction on group manifolds

DOE PAGES

Baguet, A.; Pope, Christopher N.; Samtleben, H.

2016-01-01

We prove an old conjecture by Duff, Nilsson, Pope and Warner asserting that the NSNS sector of supergravity (and more general the bosonic string) allows for a consistent Pauli reduction on any d-dimensional group manifold G, keeping the full set of gauge bosons of the G×G isometry group of the bi-invariant metric on G. The main tool of the construction is a particular generalised Scherk–Schwarz reduction ansatz in double field theory which we explicitly construct in terms of the group's Killing vectors. Examples include the consistent reduction from ten dimensions on S3×S3 and on similar product spaces. The construction ismore » another example of globally geometric non-toroidal compactifications inducing non-geometric fluxes.« less

Tensor hierarchy and generalized Cartan calculus in SL(3) × SL(2) exceptional field theory

NASA Astrophysics Data System (ADS)

Hohm, Olaf; Wang, Yi-Nan

2015-04-01

We construct exceptional field theory for the duality group SL(3) × SL(2). The theory is defined on a space with 8 `external' coordinates and 6 `internal' coordinates in the (3, 2) fundamental representation, leading to a 14-dimensional generalized spacetime. The bosonic theory is uniquely determined by gauge invariance under generalized external and internal diffeomorphisms. The latter invariance can be made manifest by introducing higher form gauge fields and a so-called tensor hierarchy, which we systematically develop to much higher degree than in previous studies. To this end we introduce a novel Cartan-like tensor calculus based on a covariant nil-potent differential, generalizing the exterior derivative of conventional differential geometry. The theory encodes the full D = 11 or type IIB supergravity, respectively.

EFT for vortices with dilaton-dependent localized flux

NASA Astrophysics Data System (ADS)

Burgess, C. P.; Diener, Ross; Williams, M.

2015-11-01

We study how codimension-two objects like vortices back-react gravitationally with their environment in theories (such as 4D or higher-dimensional supergravity) where the bulk is described by a dilaton-Maxwell-Einstein system. We do so both in the full theory, for which the vortex is an explicit classical `fat brane' solution, and in the effective theory of `point branes' appropriate when the vortices are much smaller than the scales of interest for their back-reaction (such as the transverse Kaluza-Klein scale). We extend the standard Nambu-Goto description to include the physics of flux-localization wherein the ambient flux of the external Maxwell field becomes partially localized to the vortex, generalizing the results of a companion paper [4] from N=2 supergravity as the end-point of a hierarchical limit in which the Planck mass first and then the supersymmetry breaking scale are sent to infinity. We define, in the parent supergravity model, a new symplectic frame in which, in the rigid limit, manifest symplectic invariance is preserved and the electric and magnetic Fayet-Iliopoulos terms are fully originated from the dyonic components of the embedding tensor. The supergravity origin of several features of the resulting rigid supersymmetric theory are then elucidated, such as the presence of a traceless SU(2)- Lie algebra term in the Ward identity and the existence of a central charge in the supersymmetry algebra which manifests itself as a harmless gauge transformation on the gauge vectors of the rigid theory; we show that this effect can be interpreted as a kind of "superspace non-locality" which does not affect the rigid theory on space-time. To set the stage of our analysis we take the opportunity in this paper to provide and prove the relevant identities of the most general dyonic gauging of Special-Kaehler and Quaternionic-Kaehler isometries in a generic N=2 model, which include the supersymmetry Ward identity, in a fully symplectic-covariant formalism.

Medium generated gap in gravity and a 3D gauge theory

NASA Astrophysics Data System (ADS)

Gabadadze, Gregory; Older, Daniel

2018-05-01

It is well known that a physical medium that sets a Lorentz frame generates a Lorentz-breaking gap for a graviton. We examine such generated "mass" terms in the presence of a fluid medium whose ground state spontaneously breaks spatial translation invariance in d =D +1 spacetime dimensions, and for a solid in D =2 spatial dimensions. By requiring energy positivity and subluminal propagation, certain constraints are placed on the equation of state of the medium. In the case of D =2 spatial dimensions, classical gravity can be recast as a Chern-Simons gauge theory, and motivated by this we recast the massive theory of gravity in AdS3 as a massive Chern-Simons gauge theory with an unusual mass term. We find that in the flat space limit the Chern-Simons theory has a novel gauge invariance that mixes the kinetic and mass terms, and enables the massive theory with a noncompact internal group to be free of ghosts and tachyons.

Gauged supergravities from M-theory reductions

NASA Astrophysics Data System (ADS)

Katmadas, Stefanos; Tomasiello, Alessandro

2018-04-01

In supergravity compactifications, there is in general no clear prescription on how to select a finite-dimensional family of metrics on the internal space, and a family of forms on which to expand the various potentials, such that the lower-dimensional effective theory is supersymmetric. We propose a finite-dimensional family of deformations for regular Sasaki-Einstein seven-manifolds M 7, relevant for M-theory compactifications down to four dimensions. It consists of integrable Cauchy-Riemann structures, corresponding to complex deformations of the Calabi-Yau cone M 8 over M 7. The non-harmonic forms we propose are the ones contained in one of the Kohn-Rossi cohomology groups, which is finite-dimensional and naturally controls the deformations of Cauchy-Riemann structures. The same family of deformations can be also described in terms of twisted cohomology of the base M 6, or in terms of Milnor cycles arising in deformations of M 8. Using existing results on SU(3) structure compactifications, we briefly discuss the reduction of M-theory on our class of deformed Sasaki-Einstein manifolds to four-dimensional gauged supergravity.

BFV-BRST quantization of two-dimensional supergravity

NASA Astrophysics Data System (ADS)

Fujiwara, T.; Igarashi, Y.; Kuriki, R.; Tabei, T.

1996-01-01

Two-dimensional supergravity theory is quantized as an anomalous gauge theory. In the Batalin-Fradkin (BF) formalism, the anomaly-canceling super-Liouville fields are introduced to identify the original second-class constrained system with a gauge-fixed version of a first-class system. The BFV-BRST quantization applies to formulate the theory in the most general class of gauges. A local effective action constructed in the configuration space contains two super-Liouville actions; one is a noncovariant but local functional written only in terms of two-dimensional supergravity fields, and the other contains the super-Liouville fields canceling the super-Weyl anomaly. Auxiliary fields for the Liouville and the gravity supermultiplets are introduced to make the BRST algebra close off-shell. Inclusion of them turns out to be essentially important especially in the super-light-cone gauge fixing, where the supercurvature equations (∂3-g++=∂2-χ++=0) are obtained as a result of BRST invariance of the theory. Our approach reveals the origin of the OSp(1,2) current algebra symmetry in a transparent manner.

Construction of all N=4 conformal supergravities.

PubMed

Butter, Daniel; Ciceri, Franz; de Wit, Bernard; Sahoo, Bindusar

2017-02-24

All N=4 conformal supergravities in four space-time dimensions are constructed. These are the only N=4 supergravity theories whose actions are invariant under off-shell supersymmetry. They are encoded in terms of a holomorphic function that is homogeneous of zeroth degree in scalar fields that parametrize an SU(1,1)/U(1) coset space. When this function equals a constant the Lagrangian is invariant under continuous SU(1,1) transformations. The construction of these higher-derivative invariants also opens the door to various applications for nonconformal theories.

Divergences and boundary modes in $$ \\mathcal{N}=8 $$ supergravity

DOE PAGES

Larsen, Finn; Lisbao, Pedro

2016-01-07

We reconsider the one loop divergence ofmore » $$ \\mathcal{N}=8 $$ supergravity in four dimensions. We compute the finite effective potential of $$ \\mathcal{N}=8 $$ anti-deSitter supergravity and interpret it as logarithmic running of the cosmological constant. We show that quantum inequivalence between fields that are classically dual is due to boundary modes in AdS 4. In conclusion, the boundary modes are important in global AdS 4 but not in thermal AdS 4 since these geometries have different Euler characteristic.« less

Two-field analysis of no-scale supergravity inflation

DOE PAGES

Ellis, John; Garcia, Marcos A. G.; Nanopoulos, Dimitri V.; ...

2015-01-08

Since the building-blocks of supersymmetric models include chiral superfields containing pairs of effective scalar fields, a two-field approach is particularly appropriate for models of inflation based on supergravity. In this paper, we generalize the two-field analysis of the inflationary power spectrum to supergravity models with arbitrary Kähler potential. We show how two-field effects in the context of no-scale supergravity can alter the model predictions for the scalar spectral index n s and the tensor-to-scalar ratio r, yielding results that interpolate between the Planck-friendly Starobinsky model and BICEP2-friendly predictions. In particular, we show that two-field effects in a chaotic no-scale inflationmore » model with a quadratic potential are capable of reducing r to very small values << 0.1. Here, we also calculate the non-Gaussianity measure f NL, finding that is well below the current experimental sensitivity.« less

Supersymmetric black holes and Freudenthal duality

NASA Astrophysics Data System (ADS)

Marrani, Alessio; Mandal, Taniya; Tripathy, Prasanta K.

2017-07-01

We study the effect of Freudenthal duality on supersymmetric extremal black hole attractors in 𝒩 = 2, D = 4 ungauged supergravity. Freudenthal duality acts on the dyonic black hole charges as an anti-involution which keeps the black hole entropy and the critical points of the effective black hole potential invariant. We analyze its effect on the recently discovered distinct, mutually exclusive phases of axionic supersymmetric black holes, related to the existence of nontrivial involutory constant matrices. In particular, we consider a supersymmetric D0 - D4 - D6 black hole and we explicitly Freudenthal-map it to a supersymmetric D0 - D2 - D4 - D6 black hole. We thus show that the charge representation space of a supersymmetric D0 - D2 - D4 - D6 black hole also contains mutually exclusive domains.

Selective Precipitation and Concentrating of Perovskite Crystals from Titanium-Bearing Slag Melt in Supergravity Field

NASA Astrophysics Data System (ADS)

Gao, Jintao; Zhong, Yiwei; Guo, Zhancheng

2016-08-01

Selective precipitation and concentrating of perovskite crystals from titanium-bearing slag melt in the supergravity field was investigated in this study. Since perovskite was the first precipitated phase from the slag melt during the cooling process, and a greater precipitation quantity and larger crystal sizes of perovskite were obtained at 1593 K to 1563 K (1320 °C to 1290 °C), concentrating of perovskite crystals from the slag melt was carried out at this temperature range in the supergravity field, at which the perovskite transforms into solid particles while the other minerals remain in the liquid melt. The layered structures appeared significantly in the sample obtained by supergravity treatment, and all the perovskite crystals moved along the supergravity direction and concentrated as the perovskite-rich phase in the bottom area, whereas the molten slag concentrated in the upper area along the opposite direction, in which it was impossible to find any perovskite crystals. With the gravity coefficient of G = 750, the mass fraction of TiO2 in the perovskite-rich phase was up to 34.65 wt pct, whereas that of the slag phase was decreased to 12.23 wt pct, and the recovery ratio of Ti in the perovskite-rich phase was up to 75.28 pct. On this basis, an amplification experimental centrifugal apparatus was exploited and the continuous experiment with larger scale was further carried out, the results confirming that selective precipitation and concentrating of perovskite crystals from the titanium-bearing slag melt by supergravity was a feasible method.

Topological resolution of gauge theory singularities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saracco, Fabio; Tomasiello, Alessandro; Torroba, Gonzalo

2013-08-21

Some gauge theories with Coulomb branches exhibit singularities in perturbation theory, which are usually resolved by nonperturbative physics. In string theory this corresponds to the resolution of timelike singularities near the core of orientifold planes by effects from F or M theory. We propose a new mechanism for resolving Coulomb branch singularities in three-dimensional gauge theories, based on Chern-Simons interactions. This is illustrated in a supersymmetric S U ( 2 ) Yang-Mills-Chern-Simons theory. We calculate the one-loop corrections to the Coulomb branch of this theory and find a result that interpolates smoothly between the high-energy metric (that would exhibit themore » singularity) and a regular singularity-free low-energy result. We suggest possible applications to singularity resolution in string theory and speculate a relationship to a similar phenomenon for the orientifold six-plane in massive IIA supergravity.« less

On the spectrum of gauge/gravity duals with reduced supersymmetry

NASA Astrophysics Data System (ADS)

Solovyov, Alexander

The topic of the present thesis is the study of some examples in gauge/string duality. We carefully study the orbifold gauge theory and orbifold string theory and show that the known integrability in AdS/CFT extends to the general supersymmetric orbifolds of AdS5 x S5. There is an interesting interplay between the two descriptions of the orbifold gauge theory. Another interesting example is the Klebanov-Strassler (KS) background. We find the exhaustive list of the supergravity excitations in the I -odd sector of the KS theory. These comprise the three j = 1/2 massive supermultiplets each consisting of a (possibly pseudo) scalar, two fermions and a vector, and the two j = 1 supermultiplets whose bosonic content is a vector and a pseudovector. Surprisingly, the spectrum of the excitations which fit into the pure gauge sector strongly resembles the results obtained from the numeric studies in lattice gauge theory.

Sequestered gravity in gauge mediation.

PubMed

Antoniadis, Ignatios; Benakli, Karim; Quiros, Mariano

2016-01-01

We present a novel mechanism of supersymmetry breaking embeddable in string theory and simultaneously sharing the main advantages of (sequestered) gravity and gauge mediation. It is driven by a Scherk-Schwarz deformation along a compact extra dimension, transverse to a brane stack supporting the supersymmetric extension of the Standard Model. This fixes the magnitude of the gravitino mass, together with that of the gauginos of a bulk gauge group, at a scale as high as [Formula: see text] GeV. Supersymmetry breaking is mediated to the observable sector dominantly by gauge interactions using massive messengers transforming non-trivially under the bulk and Standard Model gauge groups and leading to a neutralino LSP as dark matter candidate. The Higgsino mass [Formula: see text] and soft Higgs-bilinear [Formula: see text] term could be generated at the same order of magnitude as the other soft terms by effective supergravity couplings as in the Giudice-Masiero mechanism.

Quantum gravity in the Southern Cone Conference. Proceedings. Conference, Bariloche (Argentina), 7 - 10 Jan 1998.

NASA Astrophysics Data System (ADS)

1999-04-01

The following topics are discussed: Black hole formation by canonical dynamics of gravitating shells; canonical quantum gravity; Vassiliev invariants; midisuperspace models; quantum spacetime; large-N limit of superconformal field theories and supergravity; world-volume fields and background coupling of branes; gauge enhancement and chirality changes in nonperturbative orbifold models; chiral p-forms; formally renormalizable gravitationally self-interacting string models; gauge supergravities for all odd dimensions; black hole radiation and S-matrix; primordial black holes; fluctuations in a thermal field and dissipation of a black hole spacetime in far-field limit; adiabatic interpretation of particle creation in a de Sitter universe; nonequilibrium dynamics of quantum fields in inflationary cosmology; magnetic fields in the early Universe; classical regime of a quantum universe obtained through a functional method; decoherence and correlations in semiclassical cosmology; fluid of primordial fluctuations; causal statistical mechanics calculation of initial cosmic entropy and quantum gravity prospects and black hole-D-brane correspondence.

Quaternionic (super) twistors extensions and general superspaces

NASA Astrophysics Data System (ADS)

Cirilo-Lombardo, Diego Julio; Pervushin, Victor N.

2017-09-01

In a attempt to treat a supergravity as a tensor representation, the four-dimensional N-extended quaternionic superspaces are constructed from the (diffeomorphyc) graded extension of the ordinary Penrose-twistor formulation, performed in a previous work of the authors [D. J. Cirilo-Lombardo and V. N. Pervushin, Int. J. Geom. Methods Mod. Phys., doi: http://dx.doi.org/10.1142/S0219887816501139.], with N = p + k. These quaternionic superspaces have 4 + k(N - k) even-quaternionic coordinates and 4N odd-quaternionic coordinates, where each coordinate is a quaternion composed by four ℂ-fields (bosons and fermions respectively). The fields content as the dimensionality (even and odd sectors) of these superspaces are given and exemplified by selected physical cases. In this case, the number of fields of the supergravity is determined by the number of components of the tensor representation of the four-dimensional N-extended quaternionic superspaces. The role of tensorial central charges for any N even USp(N) = Sp(N, ℍℂ) ∩ U(N, ℍℂ) is elucidated from this theoretical context.

Refining the boundaries of the classical de Sitter landscape

NASA Astrophysics Data System (ADS)

Andriot, David; Blåbäck, Johan

2017-03-01

We derive highly constraining no-go theorems for classical de Sitter backgrounds of string theory, with parallel sources; this should impact the embedding of cosmological models. We study ten-dimensional vacua of type II supergravities with parallel and backreacted orientifold O p -planes and D p -branes, on four-dimensional de Sitter spacetime times a compact manifold. Vacua for p = 3, 7 or 8 are completely excluded, and we obtain tight constraints for p = 4, 5, 6. This is achieved through the derivation of an enlightening expression for the four-dimensional Ricci scalar. Further interesting expressions and no-go theorems are obtained. The paper is self-contained so technical aspects, including conventions, might be of more general interest.

On the stability of non-supersymmetric supergravity solutions

NASA Astrophysics Data System (ADS)

Imaanpur, Ali; Zameni, Razieh

2017-09-01

We examine the stability of some non-supersymmetric supergravity solutions that have been found recently. The first solution is AdS5 ×M6, for M6 an stretched CP3. We consider breathing and squashing mode deformations of the metric, and find that the solution is stable against small fluctuations of this kind. Next we consider type IIB solution of AdS2 ×M8, where the compact space is a U (1) bundle over N (1 , 1). We study its stability under the deformation of M8 and the 5-form flux. In this case we also find that the solution is stable under small fluctuation modes of the corresponding deformations.

Enriching and Separating Primary Copper Impurity from Pb-3 Mass Pct Cu Melt by Super-Gravity Technology

NASA Astrophysics Data System (ADS)

Yang, Yuhou; Song, Bo; Song, Gaoyang; Yang, Zhanbing; Xin, Wenbin

2016-10-01

In this study, super-gravity technology was introduced in the lead bullion-refining process to investigate the enriching and separating laws of copper impurity from Pb-3 mass pct Cu melt. With the gravity coefficient G = 700 at the cooling rate of ν = 5 K min-1, the entire copper phase gathers at the upper area of the sample, and it is hard to find any copper particles at the bottom area of the sample. The floatation movement of copper phase was greatly intensified by super gravity and the mass pct of copper in tailing lead is up to 8.631 pct, while that in the refined lead is only 0.113 pct. The refining rate of lead bullion reached up to 94.27 pct. Copper-phase impurity can be separated effectively from Pb-3 mass pct Cu melt by filtration method in super-gravity field, and the separation efficiency increased with the increasing gravity coefficient in the range of G ≥ 10. After filtration at 613 K (340 °C) with gravity coefficient G = 100 for 10 minutes, the refined lead, with just 0.157 mass pct copper impurity, was separated to the bottom of the crucible, and the copper dross containing only 23.56 mass pct residual lead was intercepted by the carbon fiber felt, leading to the separation efficiency up to 96.18 pct (meaning a great reduction in metal loss).

Progress report on PIXIE3D, a fully implicit 3D extended MHD solver

NASA Astrophysics Data System (ADS)

Chacon, Luis

2008-11-01

Recently, invited talk at DPP07 an optimal, massively parallel implicit algorithm for 3D resistive magnetohydrodynamics (PIXIE3D) was demonstrated. Excellent algorithmic and parallel results were obtained with up to 4096 processors and 138 million unknowns. While this is a remarkable result, further developments are still needed for PIXIE3D to become a 3D extended MHD production code in general geometries. In this poster, we present an update on the status of PIXIE3D on several fronts. On the physics side, we will describe our progress towards the full Braginskii model, including: electron Hall terms, anisotropic heat conduction, and gyroviscous corrections. Algorithmically, we will discuss progress towards a robust, optimal, nonlinear solver for arbitrary geometries, including preconditioning for the new physical effects described, the implementation of a coarse processor-grid solver (to maintain optimal algorithmic performance for an arbitrarily large number of processors in massively parallel computations), and of a multiblock capability to deal with complicated geometries. L. Chac'on, Phys. Plasmas 15, 056103 (2008);

Instabilities in Englert-type supergravity solutions

NASA Astrophysics Data System (ADS)

Page, Don N.; Pope, C. N.

1984-09-01

We show that all eleven-dimensional Englert-type supergravity solutions (in which the four-index field has internal components) constructed from internal spaces M7 having two or more Killing spinors, are unstable. Permanent address: Blackett Laboratory, Imperial College, London SW7 2BZ, United Kingdom.

BFV-BRST quantization of two-dimensional supergravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fujiwara, T.; Igarashi, Y.; Kuriki, R.

1996-01-01

Two-dimensional supergravity theory is quantized as an anomalous gauge theory. In the Batalin-Fradkin (BF) formalism, the anomaly-canceling super-Liouville fields are introduced to identify the original second-class constrained system with a gauge-fixed version of a first-class system. The BFV-BRST quantization applies to formulate the theory in the most general class of gauges. A local effective action constructed in the configuration space contains two super-Liouville actions; one is a noncovariant but local functional written only in terms of two-dimensional supergravity fields, and the other contains the super-Liouville fields canceling the super-Weyl anomaly. Auxiliary fields for the Liouville and the gravity supermultiplets aremore » introduced to make the BRST algebra close off-shell. Inclusion of them turns out to be essentially important especially in the super-light-cone gauge fixing, where the supercurvature equations ({partial_derivative}{sup 3}{sub {minus}}{ital g}{sub +}{sub +}={partial_derivative}{sup 2}{sub {minus}}{chi}{sub +}{sub +}=0) are obtained as a result of BRST invariance of the theory. Our approach reveals the origin of the OSp(1,2) current algebra symmetry in a transparent manner. {copyright} {ital 1996 The American Physical Society.}« less

Imaginary potential of moving quarkonia in a D-instanton background

NASA Astrophysics Data System (ADS)

Zhang, Zi-qiang; Hou, De-fu; Chen, Gang

2017-11-01

The imaginary part of the inter-quark potential of moving heavy quarkonia is investigated in the context of dual super-gravity in an AdS background, deformed by a dilaton which induces the gauge field condensate in the dual gauge theory. A quark-anti-quark pair is analyzed, moving transverse and parallel to the plasma wind, in turn. It is shown that in both cases increased D-instanton density tends to increase the inter-distance and decrease the imaginary potential, opposite to the effect of the pair’s velocity. Moreover, it is found that the D-instanton density has stronger effects in the parallel case than the transverse.

Romans supergravity from five-dimensional holograms

NASA Astrophysics Data System (ADS)

Chang, Chi-Ming; Fluder, Martin; Lin, Ying-Hsuan; Wang, Yifan

2018-05-01

We study five-dimensional superconformal field theories and their holographic dual, matter-coupled Romans supergravity. On the one hand, some recently derived formulae allow us to extract the central charges from deformations of the supersymmetric five-sphere partition function, whose large N expansion can be computed using matrix model techniques. On the other hand, the conformal and flavor central charges can be extracted from the six-dimensional supergravity action, by carefully analyzing its embedding into type I' string theory. The results match on the two sides of the holographic duality. Our results also provide analytic evidence for the symmetry enhancement in five-dimensional superconformal field theories.

Effect of Turbulence Models on Two Massively-Separated Benchmark Flow Cases

NASA Technical Reports Server (NTRS)

Rumsey, Christopher L.

2003-01-01

Two massively-separated flow cases (the 2-D hill and the 3-D Ahmed body) were computed with several different turbulence models in the Reynolds-averaged Navier-Stokes code CFL3D as part of participation in a turbulence modeling workshop held in Poitiers, France in October, 2002. Overall, results were disappointing, but were consistent with results from other RANS codes and other turbulence models at the workshop. For the 2-D hill case, those turbulence models that predicted separation location accurately ended up yielding a too-long separation extent downstream. The one model that predicted a shorter separation extent in better agreement with LES data did so only by coincidence: its prediction of earlier reattachment was due to a too-late prediction of the separation location. For the Ahmed body, two slant angles were computed, and CFD performed fairly well for one of the cases (the larger slant angle). Both turbulence models tested in this case were very similar to each other. For the smaller slant angle, CFD predicted massive separation, whereas the experiment showed reattachment about half-way down the center of the face. These test cases serve as reminders that state- of-the-art CFD is currently not a reliable predictor of massively-separated flow physics, and that further validation studies in this area would be beneficial.

The tensor hierarchy algebra

DOE Office of Scientific and Technical Information (OSTI.GOV)

Palmkvist, Jakob, E-mail: palmkvist@ihes.fr

We introduce an infinite-dimensional Lie superalgebra which is an extension of the U-duality Lie algebra of maximal supergravity in D dimensions, for 3 ⩽ D ⩽ 7. The level decomposition with respect to the U-duality Lie algebra gives exactly the tensor hierarchy of representations that arises in gauge deformations of the theory described by an embedding tensor, for all positive levels p. We prove that these representations are always contained in those coming from the associated Borcherds-Kac-Moody superalgebra, and we explain why some of the latter representations are not included in the tensor hierarchy. The most remarkable feature of ourmore » Lie superalgebra is that it does not admit a triangular decomposition like a (Borcherds-)Kac-Moody (super)algebra. Instead the Hodge duality relations between level p and D − 2 − p extend to negative p, relating the representations at the first two negative levels to the supersymmetry and closure constraints of the embedding tensor.« less

All Chern-Simons invariants of 4D, N = 1 gauged superform hierarchies

NASA Astrophysics Data System (ADS)

Becker, Katrin; Becker, Melanie; Linch, William D.; Randall, Stephen; Robbins, Daniel

2017-04-01

We give a geometric description of supersymmetric gravity/(non-)abelian p-form hierarchies in superspaces with 4D, N = 1 super-Poincaré invariance. These hierarchies give rise to Chern-Simons-like invariants, such as those of the 5D, N = 1 graviphoton and the eleven-dimensional 3-form but also generalizations such as Green-Schwarz-like/ BF -type couplings. Previous constructions based on prepotential superfields are reinterpreted in terms of p-forms in superspace thereby elucidating the underlying geometry. This vastly simplifies the calculations of superspace field-strengths, Bianchi identities, and Chern-Simons invariants. Using this, we prove the validity of a recursive formula for the conditions defining these actions for any such tensor hierarchy. Solving it at quadratic and cubic orders, we recover the known results for the BF -type and cubic Chern-Simons actions. As an application, we compute the quartic invariant ˜ AdAdAdA + . . . relevant, for example, to seven-dimensional supergravity compactifications.

Rotator cuff tear shape characterization: a comparison of two-dimensional imaging and three-dimensional magnetic resonance reconstructions.

PubMed

Gyftopoulos, Soterios; Beltran, Luis S; Gibbs, Kevin; Jazrawi, Laith; Berman, Phillip; Babb, James; Meislin, Robert

2016-01-01

The purpose of this study was to see if 3-dimensional (3D) magnetic resonance imaging (MRI) could improve our understanding of rotator cuff tendon tear shapes. We believed that 3D MRI would be more accurate than two-dimensional (2D) MRI for classifying tear shapes. We performed a retrospective review of MRI studies of patients with arthroscopically proven full-thickness rotator cuff tears. Two orthopedic surgeons reviewed the information for each case, including scope images, and characterized the shape of the cuff tear into crescent, longitudinal, U- or L-shaped longitudinal, and massive type. Two musculoskeletal radiologists reviewed the corresponding MRI studies independently and blind to the arthroscopic findings and characterized the shape on the basis of the tear's retraction and size using 2D MRI. The 3D reconstructions of each cuff tear were reviewed by each radiologist to characterize the shape. Statistical analysis included 95% confidence intervals and intraclass correlation coefficients. The study reviewed 34 patients. The accuracy for differentiating between crescent-shaped, longitudinal, and massive tears using measurements on 2D MRI was 70.6% for reader 1 and 67.6% for reader 2. The accuracy for tear shape characterization into crescent and longitudinal U- or L-shaped using 3D MRI was 97.1% for reader 1 and 82.4% for reader 2. When further characterizing the longitudinal tears as massive or not using 3D MRI, both readers had an accuracy of 76.9% (10 of 13). The overall accuracy of 3D MRI was 82.4% (56 of 68), significantly different (P = .021) from 2D MRI accuracy (64.7%). Our study has demonstrated that 3D MR reconstructions of the rotator cuff improve the accuracy of characterizing rotator cuff tear shapes compared with current 2D MRI-based techniques. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Sound Speed of Primordial Fluctuations in Supergravity Inflation.

PubMed

Hetz, Alexander; Palma, Gonzalo A

2016-09-02

We study the realization of slow-roll inflation in N=1 supergravities where inflation is the result of the evolution of a single chiral field. When there is only one flat direction in field space, it is possible to derive a single-field effective field theory parametrized by the sound speed c_{s} at which curvature perturbations propagate during inflation. The value of c_{s} is determined by the rate of bend of the inflationary path resulting from the shape of the F-term potential. We show that c_{s} must respect an inequality that involves the curvature tensor of the Kähler manifold underlying supergravity, and the ratio M/H between the mass M of fluctuations ortogonal to the inflationary path, and the Hubble expansion rate H. This inequality provides a powerful link between observational constraints on primordial non-Gaussianity and information about the N=1 supergravity responsible for inflation. In particular, the inequality does not allow for suppressed values of c_{s} (values smaller than c_{s}∼0.4) unless (a) the ratio M/H is of order 1 or smaller, and (b) the fluctuations of mass M affect the propagation of curvature perturbations by inducing on them a nonlinear dispersion relation during horizon crossing. Therefore, if large non-Gaussianity is observed, supergravity models of inflation would be severely constrained.

Comparative Analysis of Data Structures for Storing Massive Tins in a Dbms

NASA Astrophysics Data System (ADS)

Kumar, K.; Ledoux, H.; Stoter, J.

2016-06-01

Point cloud data are an important source for 3D geoinformation. Modern day 3D data acquisition and processing techniques such as airborne laser scanning and multi-beam echosounding generate billions of 3D points for simply an area of few square kilometers. With the size of the point clouds exceeding the billion mark for even a small area, there is a need for their efficient storage and management. These point clouds are sometimes associated with attributes and constraints as well. Storing billions of 3D points is currently possible which is confirmed by the initial implementations in Oracle Spatial SDO PC and the PostgreSQL Point Cloud extension. But to be able to analyse and extract useful information from point clouds, we need more than just points i.e. we require the surface defined by these points in space. There are different ways to represent surfaces in GIS including grids, TINs, boundary representations, etc. In this study, we investigate the database solutions for the storage and management of massive TINs. The classical (face and edge based) and compact (star based) data structures are discussed at length with reference to their structure, advantages and limitations in handling massive triangulations and are compared with the current solution of PostGIS Simple Feature. The main test dataset is the TIN generated from third national elevation model of the Netherlands (AHN3) with a point density of over 10 points/m2. PostgreSQL/PostGIS DBMS is used for storing the generated TIN. The data structures are tested with the generated TIN models to account for their geometry, topology, storage, indexing, and loading time in a database. Our study is useful in identifying what are the limitations of the existing data structures for storing massive TINs and what is required to optimise these structures for managing massive triangulations in a database.

The Eta Carinae Homunculus in Full 3D with X-Shooter and Shape

NASA Technical Reports Server (NTRS)

Steffen, Wolfgang; Teodoro, Mairan; Madura, Thomas I.; Groh, Jose H.; Gull, Theodore R.; Mehner, Andrea; Corcoran, Michael F.; Damineli, Augusto; Hamaguchi, Kenji

2014-01-01

Massive stars like Eta Carinae are extremely rare in comparison to stars such as the Sun, and currently we know of only a handful of stars with masses of more than 100 solar mass in the Milky Way. Such massive stars were much more frequent in the early history of the Universe and had a huge impact on its evolution. Even among this elite club, Eta Car is outstanding, in particular because of its giant eruption around 1840 that produced the beautiful bipolar nebula now known as the Homunculus. In this study, we used detailed spatio-kinematic information obtained from X-shooter spectra to reconstruct the 3D structure of the Homunculus. The small-scale features suggest that the central massive binary played a significant role in shaping the Homunculus.

Gravity with a cosmological constant from rational curves

NASA Astrophysics Data System (ADS)

Adamo, Tim

2015-11-01

We give a new formula for all tree-level correlators of boundary field insertions in gauged N=8 supergravity in AdS4; this is an analogue of the tree-level S-matrix in anti-de Sitter space. The formula is written in terms of rational maps from the Riemann sphere to twistor space, with no reference to bulk perturbation theory. It is polynomial in the cosmological constant, and equal to the classical scattering amplitudes of supergravity in the flat space limit. The formula is manifestly supersymmetric, independent of gauge choices on twistor space, and equivalent to expressions computed via perturbation theory at 3-point overline{MHV} and n-point MHV. We also show that the formula factorizes and obeys BCFW recursion in twistor space.

Constraining higher derivative supergravity with scattering amplitudes

DOE PAGES

Wang, Yifan; Yin, Xi

2015-08-31

We study supersymmetry constraints on higher derivative deformations of type IIB supergravity by consideration of superamplitudes. Thus, combining constraints of on-shell supervertices and basic results from string perturbation theory, we give a simple argument for the non-renormalization theorem of Green and Sethi, and some of its generalizations.

Supersymmetric M3-branes and G2 manifolds

NASA Astrophysics Data System (ADS)

Cvetič, M.; Gibbons, G. W.; Lü, H.; Pope, C. N.

2002-01-01

We obtain a generalisation of the original complete Ricci-flat metric of G2 holonomy on R4×S 3 to a family with a nontrivial parameter λ. For generic λ the solution is singular, but it is regular when λ={-1,0,+1}. The case λ=0 corresponds to the original G2 metric, and λ={-1,1} are related to this by an S3 automorphism of the SU(2) 3 isometry group that acts on the S3× S3 principal orbits. We then construct explicit supersymmetric M3-brane solutions in D=11 supergravity, where the transverse space is a deformation of this class of G2 metrics. These are solutions of a system of first-order differential equations coming from a superpotential. We also find M3-branes in the deformed backgrounds of new G2 holonomy metrics that include one found by A. Brandhuber, J. Gomis, S. Gubser and S. Gukov, and show that they also are supersymmetric.

On the topology of the inflaton field in minimal supergravity models

NASA Astrophysics Data System (ADS)

Ferrara, Sergio; Fré, Pietro; Sorin, Alexander S.

2014-04-01

We consider global issues in minimal supergravity models where a single field inflaton potential emerges. In a particular case we reproduce the Starobinsky model and its description dual to a certain formulation of R + R 2 supergravity. For definiteness we confine our analysis to spaces at constant curvature, either vanishing or negative. Five distinct models arise, two flat models with respectively a quadratic and a quartic potential and three based on the space where its distinct isometries, elliptic, hyperbolic and parabolic are gauged. Fayet-Iliopoulos terms are introduced in a geometric way and they turn out to be a crucial ingredient in order to describe the de Sitter inflationary phase of the Starobinsky model.

Spontaneously broken Yang-Mills-Einstein supergravities as double copies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiodaroli, Marco; Günaydin, Murat; Johansson, Henrik

Color/kinematics duality and the double-copy construction have proved to be systematic tools for gaining new insight into gravitational theories. Extending our earlier work, in this article we introduce new double-copy constructions for large classes of spontaneously-broken Yang-Mills-Einstein theories with adjoint Higgs elds. One gaugetheory copy entering the construction is a spontaneously-broken (super-)Yang-Mills theory, while the other copy is a bosonic Yang-Mills-scalar theory with trilinear scalar interactions that display an explicitly-broken global symmetry. We show that the kinematic numerators of these gauge theories can be made to obey color/kinematics duality by exhibiting particular additional Lie-algebraic relations. We discuss in detail explicitmore » examples with N = 2 supersymmetry, focusing on Yang-Mills-Einstein supergravity theories belonging to the generic Jordan family in four and five dimensions, and identify the map between the supergravity and double-copy elds and parameters. We also briefly discuss the application of our results to N = 4 supergravity theories. The constructions are illustrated by explicit examples of tree-level and one-loop scattering amplitudes.« less

Spontaneously broken Yang-Mills-Einstein supergravities as double copies

DOE PAGES

Chiodaroli, Marco; Günaydin, Murat; Johansson, Henrik; ...

2017-06-13

Color/kinematics duality and the double-copy construction have proved to be systematic tools for gaining new insight into gravitational theories. Extending our earlier work, in this article we introduce new double-copy constructions for large classes of spontaneously-broken Yang-Mills-Einstein theories with adjoint Higgs elds. One gaugetheory copy entering the construction is a spontaneously-broken (super-)Yang-Mills theory, while the other copy is a bosonic Yang-Mills-scalar theory with trilinear scalar interactions that display an explicitly-broken global symmetry. We show that the kinematic numerators of these gauge theories can be made to obey color/kinematics duality by exhibiting particular additional Lie-algebraic relations. We discuss in detail explicitmore » examples with N = 2 supersymmetry, focusing on Yang-Mills-Einstein supergravity theories belonging to the generic Jordan family in four and five dimensions, and identify the map between the supergravity and double-copy elds and parameters. We also briefly discuss the application of our results to N = 4 supergravity theories. The constructions are illustrated by explicit examples of tree-level and one-loop scattering amplitudes.« less

An /N=2 gauge theory and its supergravity dual

NASA Astrophysics Data System (ADS)

Brandhuber, A.; Sfetsos, K.

2000-09-01

We study flows on the scalar manifold of /N=8 gauged supergravity in five dimensions which are dual to certain mass deformations of /N=4 super Yang-Mills theory. In particular, we consider a perturbation of the gauge theory by a mass term for the adjoint hyper-multiplet, giving rise to an /N=2 theory. The exact solution of the 5-dim gauged supergravity equations of motion is found and the metric is uplifted to a ten-dimensional background of type-IIB supergravity. Using these geometric data and the AdS/CFT correspondence we analyze the spectra of certain operators as well as Wilson loops on the dual gauge theory side. The physical flows are parametrized by a single non-positive constant and describe part of the Coulomb branch of the /N=2 theory at strong coupling. We also propose a general criterion to distinguish between `physical' and `unphysical' curvature singularities. Applying it in many backgrounds arising within the AdS/CFT correspondence we find results that are in complete agreement with field theory expectations.

Final Project Report for DOE Grant NO.: DE-SC0010534 Period: Sept 2013-March 31, 2016

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gunaydin, Murat

2016-08-01

Higher spin theories has been an active area of research in recent years. One of the main research activities of the PI Murat Gunaydin over the period of this grant has been the application of quasiconformal methods to construct and study higher spin (HS) algebras and superalgebras in various dimensions. Over the past decade work on amplitudes in gauge theories, supergravity and string theories has been a very active area of research. Enormous progress has been made in the understanding of the structure of amplitudes in these theories. The novel methods and results obtained have made it possible to domore » calculations in gauge theories and supergravity theories that go well beyond the calculations one can do using the old-fashioned Feynman diagram techniques. Work on amplitudes in matter-coupled supergravity theories has been the second main focus of the PI during the funding period. The previous work of the PI on supergravity theories has played a fundamentally important role in the current work on amplitudes.« less

Removal of phosphorus-rich phase from high-phosphorous iron ore by melt separation at 1573 K in a super-gravity field

NASA Astrophysics Data System (ADS)

Gao, Jin-tao; Guo, Lei; Zhong, Yi-wei; Ren, Hong-ru; Guo, Zhan-cheng

2016-07-01

A new approach of removing the phosphorus-rich phase from high-phosphorous iron ore by melt separation at 1573 K in a super- gravity field was investigated. The iron-slag separation by super-gravity resulted in phosphorus being effectively removed from the iron-rich phase and concentrated as a phosphorus-rich phase at a temperature below the melting point of iron. The samples obtained by super-gravity exhibited obvious layered structures. All the iron grains concentrated at the bottom of the sample along the super-gravity direction, whereas the molten slag concentrated in the upper part of the sample along the opposite direction. Meanwhile, fine apatite crystals collided and grew into larger crystals and concentrated at the slag-iron interface. Consequently, in the case of centrifugation with a gravity coefficient of G = 900, the mass fractions of the slag phase and iron-rich phase were similar to their respective theoretical values. The mass fraction of MFe in the iron-rich phase was as high as 97.77wt% and that of P was decreased to 0.092wt%.

A note on the Hyper-CR equation, and gauged N = 2 supergravity

NASA Astrophysics Data System (ADS)

Dunajski, Maciej; Gutowski, Jan; Sabra, Wafic

2018-05-01

We construct a new class of solutions to the dispersionless hyper-CR equation, and show how any solution to this equation gives rise to a supersymmetric Einstein-Maxwell cosmological space-time in (3 + 1)-dimensions.

Evolved massive stars in W33 and in GMC 23.3-0.3

NASA Astrophysics Data System (ADS)

Messineo, Maria; Clark, J. Simon; Figer, Donald F.; Menten, Karl M.; Kudritzki, Rolf-Peter; Najarro, Francisco; Rich, Michael; Ivanov, Valentin D.; Valenti, Elena; Trombley, Christine; Chen, Rosie; Davies, Ben; MacKenty, John W.

2015-08-01

We have conducted an infrared spectroscopic survey for massive evolved stars and/or clusters in the Galactic giant molecular clouds G23.3-0.3 and W33. A large number of extraordinary sub-clumps/clusters of massive stars were detected. The spatial and temporal distribution of these massive stars yields information on the star formation history of the clouds.In G23.3-0.3, we discovered a dozen massive O-type stars, one candidate luminous blue variable, and several red supergiants. The O-type stars have masses from 25 to 50 Msun and ages of 5-8 Myr, while the RSGs belong to a burst that occurred 20-30 Myr ago. Therefore, GMC G23.3-0.3 has had one of the longest known histories of star formation (20-30 Myr). GMC G23.3-0.3 is rich in HII regions and supernova remnants; we detected massive stars in the cores of SNR W41 and of SNR G22.7-0.2.In W33, we detected a few evolved O-type stars and one Wolf-Rayet star, but none of the late-type objects has the luminosity of a red supergiant. W33 is characterized by discrete sources and has had at least 3-5 Myr of star formation history, which is now propagating from west to east. While our detections of massive evolved stars in W33 are made on the west side of the cloud, several dense molecular cores that may harbor proto clusters have recently been detected on the east side of the cloud by Immer et al. (2014).Messineo, Maria; Menten, Karl M.; Figer, Donald F.; Davies, Ben; Clark, J. Simon; Ivanov, Valentin D.Kudritzki, Rolf-Peter; Rich, R. Michael; MacKenty, John W.; Trombley, Christine 2014A&A...569A..20MMessineo, Maria; Clark, J. Simon; Figer, Donald F.; Kudritzki, Rolf-Peter; Francisco, Najarro; Rich, R. Michael; Menten, Karl M.; Ivanov, Valentin D.; Valenti, Elena; Trombley, Christine; Chen, C.H. Rosie; Davies, Ben; submitted to ApJ.

Black holes in higher spin supergravity

NASA Astrophysics Data System (ADS)

Datta, Shouvik; David, Justin R.

2013-07-01

We study black hole solutions in Chern-Simons higher spin supergravity based on the superalgebra sl(3|2). These black hole solutions have a U(1) gauge field and a spin 2 hair in addition to the spin 3 hair. These additional fields correspond to the R-symmetry charges of the supergroup sl(3|2). Using the relation between the bulk field equations and the Ward identities of a CFT with {N} = 2 super- {{{W}}_3} symmetry, we identify the bulk charges and chemical potentials with those of the boundary CFT. From these identifications we see that a suitable set of variables to study this black hole is in terms of the charges present in three decoupled bosonic sub-algebras of the {N} = 2 super- {{{W}}_3} algebra. The entropy and the partition function of these R-charged black holes are then evaluated in terms of the charges of the bulk theory as well as in terms of its chemical potentials. We then compute the partition function in the dual CFT and find exact agreement with the bulk partition function.

Axionic D3-D7 inflation

NASA Astrophysics Data System (ADS)

Burgess, C. P.; Cline, J. M.; Postma, M.

2009-03-01

We study the motion of a D3 brane moving within a Type IIB string vacuum compactified to 4D on K3 × T2/Z2 in the presence of D7 and O7 planes. We work within the effective 4D supergravity describing how the mobile D3 interacts with the lightest bulk moduli of the compactification, including the effects of modulus-stabilizing fluxes. We seek inflationary solutions to the resulting equations, performing our search numerically in order to avoid resorting to approximate parameterizations of the low-energy potential. We consider uplifting from D-terms and from the supersymmetry-breaking effects of anti-D3 branes. We find examples of slow-roll inflation (with anti-brane uplifting) with the mobile D3 moving along the toroidal directions, falling towards a D7-O7 stack starting from the antipodal point. The inflaton turns out to be a linear combination of the brane position and the axionic partner of the K3 volume modulus, and the similarity of the potential along the inflaton direction with that of racetrack inflation leads to the prediction ns <= 0.95 for the spectral index. The slow roll is insensitive to most of the features of the effective superpotential, and requires a one-in-104 tuning to ensure that the torus is close to square in shape. We also consider D-term inflation with the D3 close to the attractive D7, but find that for a broad (but not exhaustive) class of parameters the conditions for slow roll tend to destabilize the bulk moduli. In contrast to the axionic case, the best inflationary example of this kind requires the delicate adjustment of potential parameters (much more than the part-per-mille level), and gives inflation only at an inflection point of the potential (and so suffers from additional fine-tuning of initial conditions to avoid an overshoot problem).

Dynamical symmetry enhancement near N = 2, D = 4 gauged supergravity horizons

NASA Astrophysics Data System (ADS)

Gutowski, J.; Mohaupt, T.; Papadopoulos, G.

2017-03-01

We show that all smooth Killing horizons with compact horizon sections of 4-dimensional gauged N = 2 supergravity coupled to any number of vector multiplets preserve 2{c}_1(K)+4ℓ supersymmetries, where K is a pull-back of the Hodge bundle of the special Kähler manifold on the horizon spatial section. We also demonstrate that all such horizons with {c}_1(K)=0 exhibit an sl(2,R) symmetry and preserve either 4 or 8 supersymmetries. If the orbits of the sl(2,R) symmetry are 2-dimensional, the horizons are warped products of AdS2 with the horizon spatial section. Otherwise, the horizon section admits an isometry which preserves all the fields. The proof of these results is centered on the use of index theorem in conjunction with an appropriate generalization of the Lichnerowicz theorem for horizons that preserve at least one supersymmetry. In all {c}_1(K)=0 cases, we specify the local geometry of spatial horizon sections and demonstrate that the solutions are determined by first order non-linear ordinary differential equations on some of the fields.

Warm p-soup and near extremal black holes

NASA Astrophysics Data System (ADS)

Morita, Takeshi; Shiba, Shotaro; Wiseman, Toby; Withers, Benjamin

2014-04-01

We consider a model of D-dimensional supergravity coupled to elementary p-branes. We use gravitational arguments to deduce the low energy effective theory of N nearly parallel branes. This is a (p + 1)-dimensional scalar field theory, where the scalars represent the positions of the branes in their transverse space. We propose that the same theory in a certain temperature regime describes a ‘soup’ of strongly interacting branes, giving a microscopic description of near extremal black p-branes. We use natural approximations to estimate the energy density of this soup as a function of the physical parameters; N, temperature, brane tension and gravitational coupling. We also characterize the horizon radius, measured in the metric natural to the branes, with the thermal vev of the scalars. For both quantities we find agreement with the corresponding supergravity black brane results. Surprisingly, beyond the physical parameters, we are naturally able to reproduce certain irrational factors such as πs. We comment on how these ideas may explain why black hole thermodynamics arises in gauge theories with holographic duals at finite temperature.

Two kissing bolts

NASA Astrophysics Data System (ADS)

Bossard, Guillaume; Katmadas, Stefanos; Turton, David

2018-02-01

The study of non-supersymmetric black hole microstates offers the potential to resolve the black hole information paradox. A system of equations was recently obtained that enables the systematic construction of non-supersymmetric smooth horizonless supergravity solutions, that are candidates to describe microstates of non-extremal black holes. Within this system we construct a family of six-dimensional supergravity solutions that feature two topologically-nontrivial three-cycles known as bolts. The two bolts touch at a single point and are supported by fluxes. We find that the fluxes on the two three-cycles can be either aligned or anti-aligned, and exhibit examples of both. We present several examples of smooth solutions, including near-extremal solutions that have an approximate AdS3 region, and far-from extremal solutions that have arbitrarily small charge compared to their mass.

Eta Carinae in the Context of the Most Massive Stars

NASA Technical Reports Server (NTRS)

Gull, Theodore R.; Damineli, Augusto

2009-01-01

Eta Car, with its historical outbursts, visible ejecta and massive, variable winds, continues to challenge both observers and modelers. In just the past five years over 100 papers have been published on this fascinating object. We now know it to be a massive binary system with a 5.54-year period. In January 2009, Car underwent one of its periodic low-states, associated with periastron passage of the two massive stars. This event was monitored by an intensive multi-wavelength campaign ranging from -rays to radio. A large amount of data was collected to test a number of evolving models including 3-D models of the massive interacting winds. August 2009 was an excellent time for observers and theorists to come together and review the accumulated studies, as have occurred in four meetings since 1998 devoted to Eta Car. Indeed, Car behaved both predictably and unpredictably during this most recent periastron, spurring timely discussions. Coincidently, WR140 also passed through periastron in early 2009. It, too, is a intensively studied massive interacting binary. Comparison of its properties, as well as the properties of other massive stars, with those of Eta Car is very instructive. These well-known examples of evolved massive binary systems provide many clues as to the fate of the most massive stars. What are the effects of the interacting winds, of individual stellar rotation, and of the circumstellar material on what we see as hypernovae/supernovae? We hope to learn. Topics discussed in this 1.5 day Joint Discussion were: Car: the 2009.0 event: Monitoring campaigns in X-rays, optical, radio, interferometry WR140 and HD5980: similarities and differences to Car LBVs and Eta Carinae: What is the relationship? Massive binary systems, wind interactions and 3-D modeling Shapes of the Homunculus & Little Homunculus: what do we learn about mass ejection? Massive stars: the connection to supernovae, hypernovae and gamma ray bursters Where do we go from here? (future directions) The Science Organizing Committee: Co-chairs: Augusto Damineli (Brazil) & Theodore R. Gull (USA). Members: D. John Hillier (USA), Gloria Koenigsberger (Mexico), Georges Meynet (Switzerland), Nidia Morrell (Chile), Atsuo T. Okazaki (Japan), Stanley P. Owocki (USA), Andy M.T. Pol- lock (Spain), Nathan Smith (USA), Christiaan L. Sterken (Belgium), Nicole St Louis (Canada), Karel A. van der Hucht (Netherlands), Roberto Viotti (Italy) and GerdWeigelt (Germany)

String-inspired supergravity model at one loop

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gaillard, M.K.; Papadopoulos, A.; Pierce, D.M.

1992-03-15

We study a prototype supergravity model from superstrings, with three generations of matter fields in the untwisted sector, nonperturbatively induced supersymmetry breaking and including threshold corrections in conformity with modular invariance. The scale degeneracy of the vacuum is lifted at the one-loop level, allowing a determination of the fundamental parameters of the effective low-energy theory.

N =4 supergravity next-to-maximally-helicity-violating six-point one-loop amplitude

NASA Astrophysics Data System (ADS)

Dunbar, David C.; Perkins, Warren B.

2016-12-01

We construct the six-point, next-to-maximally-helicity-violating one-loop amplitude in N =4 supergravity using unitarity and recursion. The use of recursion requires the introduction of rational descendants of the cut-constructible pieces of the amplitude and the computation of the nonstandard factorization terms arising from the loop integrals.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramirez, C.; Rosales, E.

General relativity can be formulated as a SU(2) BF-theory with constraints, as shown by Plebanski. Jacobson has given a SL(2, C) invariant fermionic extension of it, from which supergravity turns out [6]. We present a supersymmetric, Sp(2|1) invariant extension of the theory of Plebanski. Consistency requires that the constraints are properly generalized, resulting as well the action of supergravity.

Asymptotic structure of N=2 supergravity in 3D: extended super-BMS3 and nonlinear energy bounds

NASA Astrophysics Data System (ADS)

Fuentealba, Oscar; Matulich, Javier; Troncoso, Ricardo

2017-09-01

The asymptotically flat structure of N=(2,0) supergravity in three spacetime dimensions is explored. The asymptotic symmetries are found to be spanned by an extension of the super-BMS3 algebra, endowed with two independent affine û(1) currents of electric and magnetic type. These currents are associated to U(1) fields being even and odd under parity, respectively. Remarkably, although the U(1) fields do not generate a backreaction on the metric, they provide nontrivial Sugawara-like contributions to the BMS3 generators, and hence to the energy and the angular momentum. Consequently, the entropy of flat cosmological spacetimes endowed with U(1) fields acquires a nontrivial dependence on the zero modes of the û(1) charges. If the spin structure is odd, the ground state corresponds to Minkowski spacetime, and although the anticommutator of the canonical supercharges is linear in the energy and in the electric-like û(1) charge, the energy becomes bounded from below by the energy of the ground state shifted by the square of the electric-like û(1) charge. If the spin structure is even, the same bound for the energy generically holds, unless the absolute value of the electric-like charge is less than minus the mass of Minkowski spacetime in vacuum, so that the energy has to be nonnegative. The explicit form of the global and asymptotic Killing spinors is found for a wide class of configurations that fulfills our boundary conditions, and they exist precisely when the corresponding bounds are saturated. It is also shown that the spectra with periodic or antiperiodic boundary conditions for the fermionic fields are related by spectral flow, in a similar way as it occurs for the N=2 super-Virasoro algebra. Indeed, our supersymmetric extension of BMS3 can be recovered from the Inönü-Wigner contraction of the superconformal algebra with N=(2,2) , once the fermionic generators of the right copy are truncated.

On asymptotic freedom and confinement from type-IIB supergravity

NASA Astrophysics Data System (ADS)

Kehagias, A.; Sfetsos, K.

1999-06-01

We present a new type-IIB supergravity vacuum that describes the strong coupling regime of a non-supersymmetric gauge theory. The latter has a running coupling such that the theory becomes asymptotically free in the ultraviolet. It also has a running theta angle due to a non-vanishing axion field in the supergravity solution. We also present a worm-hole solution, which has finite action per unit four-dimensional volume and two asymptotic regions, a flat space and an AdS5xS5. The corresponding N=2 gauge theory, instead of being finite, has a running coupling. We compute the quark-antiquark potential in this case and find that it exhibits, under certain assumptions, an area-law behaviour for large separations.

Classical theory of radiating strings

NASA Technical Reports Server (NTRS)

Copeland, Edmund J.; Haws, D.; Hindmarsh, M.

1990-01-01

The divergent part of the self force of a radiating string coupled to gravity, an antisymmetric tensor and a dilaton in four dimensions are calculated to first order in classical perturbation theory. While this divergence can be absorbed into a renormalization of the string tension, demanding that both it and the divergence in the energy momentum tensor vanish forces the string to have the couplings of compactified N = 1 D = 10 supergravity. In effect, supersymmetry cures the classical infinities.

The Status of Multi-Dimensional Core-Collapse Supernova Models

NASA Astrophysics Data System (ADS)

Müller, B.

2016-09-01

Models of neutrino-driven core-collapse supernova explosions have matured considerably in recent years. Explosions of low-mass progenitors can routinely be simulated in 1D, 2D, and 3D. Nucleosynthesis calculations indicate that these supernovae could be contributors of some lighter neutron-rich elements beyond iron. The explosion mechanism of more massive stars remains under investigation, although first 3D models of neutrino-driven explosions employing multi-group neutrino transport have become available. Together with earlier 2D models and more simplified 3D simulations, these have elucidated the interplay between neutrino heating and hydrodynamic instabilities in the post-shock region that is essential for shock revival. However, some physical ingredients may still need to be added/improved before simulations can robustly explain supernova explosions over a wide range of progenitors. Solutions recently suggested in the literature include uncertainties in the neutrino rates, rotation, and seed perturbations from convective shell burning. We review the implications of 3D simulations of shell burning in supernova progenitors for the `perturbations-aided neutrino-driven mechanism,' whose efficacy is illustrated by the first successful multi-group neutrino hydrodynamics simulation of an 18 solar mass progenitor with 3D initial conditions. We conclude with speculations about the impact of 3D effects on the structure of massive stars through convective boundary mixing.

Search for charged massive long-lived particles at D0

NASA Astrophysics Data System (ADS)

Xie, Yunhe

2009-05-01

We report on a new search for charged massive long-lived particles (CMLLP) by the D0 Experiment at Fermilab's Teva- tron. CMLLP are predicted in many theories beyond Standard Model. Time-of-flight information was used in the search for pair-produced CMLLPs, based on the signature of two particles, reconstructed as muons, with speed and invariant mass inconsistent with beam-produced muons. The analysis was done with the data taken by D0 detector in Run II cor- responding to an integrated luminosity of 3 fb-1. Limits on the pair production of CMLLPs are presented quasi-model independently.

Low energy supergravity: R-parity breaking and the top quark mass

NASA Astrophysics Data System (ADS)

Carena, Marcela S.; Wagner, Carlos E. M.

1987-03-01

We study the process of spontaneous R-parity breaking in minimal low energy supergravity models. We show that it is very hard to obtain models with heavy top quarks if one wants to preserve the radiative breaking of SU(2)L⊗U(1)Y without breaking R-parity. Fellow of Consejo National de Investigaciones Cientificas y Tecnicas.

Classical stability of M/sup p/qr, Q/sup p/qr, and N/sup p/qr in d = 11 supergravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yasuda, O.

1984-09-24

We investigate the classical stability of Freund-Rubin--type solutions M/sup p/qr (SU(3) x SU(2) x U(1)/SU(2) x U(1) x U(1)), Q/sup p/qr (SU(2) x SU(2) x SU(2)/U(1) x U(1)), and N/sup p/qr (SU(3) x U(1)/U(1) x U(1)) against relative dilatations between the coset directions. It is shown that M/sup p/qr is stable only for (98/243)< or =p/sup 2//q/sup 2/< or =(6358/ 4563), Q/sup p/qr is stable only for a certain region of p/sup 2//r/sup 2/ and q/sup 2//r/sup 2/, while N/sup p/qr is stable for any p/sup 2//q/sup 2/ against these small fluctuations.

Magneto-Optics of Massive Dirac Fermions in Bulk Bi2Se3

NASA Astrophysics Data System (ADS)

Orlita, M.; Piot, B. A.; Martinez, G.; Kumar, N. K. Sampath; Faugeras, C.; Potemski, M.; Michel, C.; Hankiewicz, E. M.; Brauner, T.; Drašar, Č.; Schreyeck, S.; Grauer, S.; Brunner, K.; Gould, C.; Brüne, C.; Molenkamp, L. W.

2015-05-01

We report on magneto-optical studies of Bi2Se3, a representative member of the 3D topological insulator family. Its electronic states in bulk are shown to be well described by a simple Dirac-type Hamiltonian for massive particles with only two parameters: the fundamental band gap and the band velocity. In a magnetic field, this model implies a unique property—spin splitting equal to twice the cyclotron energy: Es=2 Ec. This explains the extensive magnetotransport studies concluding a fortuitous degeneracy of the spin and orbital split Landau levels in this material. The Es=2 Ec match differentiates the massive Dirac electrons in bulk Bi2Se3 from those in quantum electrodynamics, for which Es=Ec always holds.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Birkedal-Hansen, A.; Binetruy, P.; Mambrini, Y.

We provide a detailed study of the phenomenology of orbifold compactifications of the heterotic string within the context of supergravity effective theories. Our investigation focuses on those models where the soft Lagrangian is dominated by loop contributions to the various soft supersymmetry breaking parameters. Such models typically predict non-universal soft masses and are thus significantly different from minimal supergravity and other universal models. We consider the pattern of masses that are governed by these soft terms and investigate the implications of certain indirect constraints on supersymmetric models, such as flavor-changing neutral currents, the anomalous magnetic moment of the muon andmore » the density of thermal relic neutralinos. These string-motivated models show novel behavior that interpolates between the phenomenology of unified supergravity models and models dominated by the superconformal anomaly.« less

"MASSIVE" brain dataset: Multiple acquisitions for standardization of structural imaging validation and evaluation.

PubMed

Froeling, Martijn; Tax, Chantal M W; Vos, Sjoerd B; Luijten, Peter R; Leemans, Alexander

2017-05-01

In this work, we present the MASSIVE (Multiple Acquisitions for Standardization of Structural Imaging Validation and Evaluation) brain dataset of a single healthy subject, which is intended to facilitate diffusion MRI (dMRI) modeling and methodology development. MRI data of one healthy subject (female, 25 years) were acquired on a clinical 3 Tesla system (Philips Achieva) with an eight-channel head coil. In total, the subject was scanned on 18 different occasions with a total acquisition time of 22.5 h. The dMRI data were acquired with an isotropic resolution of 2.5 mm 3 and distributed over five shells with b-values up to 4000 s/mm 2 and two Cartesian grids with b-values up to 9000 s/mm 2 . The final dataset consists of 8000 dMRI volumes, corresponding B 0 field maps and noise maps for subsets of the dMRI scans, and ten three-dimensional FLAIR, T 1 -, and T 2 -weighted scans. The average signal-to-noise-ratio of the non-diffusion-weighted images was roughly 35. This unique set of in vivo MRI data will provide a robust framework to evaluate novel diffusion processing techniques and to reliably compare different approaches for diffusion modeling. The MASSIVE dataset is made publically available (both unprocessed and processed) on www.massive-data.org. Magn Reson Med 77:1797-1809, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Minimalism in inflation model building

NASA Astrophysics Data System (ADS)

Dvali, Gia; Riotto, Antonio

1998-01-01

In this paper we demand that a successful inflationary scenario should follow from a model entirely motivated by particle physics considerations. We show that such a connection is indeed possible within the framework of concrete supersymmetric Grand Unified Theories where the doublet-triplet splitting problem is naturally solved. The Fayet-Iliopoulos D-term of a gauge U(1)ξ symmetry, which plays a crucial role in the solution of the doublet-triplet splitting problem, simultaneously provides a built-in inflationary slope protected from dangerous supergravity corrections.

String splitting and strong coupling meson decay.

PubMed

Cotrone, A L; Martucci, L; Troost, W

2006-04-14

We study the decay of high spin mesons using the gauge-string theory correspondence. The rate of the process is calculated by studying the splitting of a macroscopic string intersecting a D-brane. The result is applied to the decay of mesons in N=4 super Yang-Mills theory with a small number of flavors and in a gravity dual of large N QCD. In QCD the decay of high spin mesons is found to be heavily suppressed in the regime of validity of the supergravity description.

Spin-3 topologically massive gravity

NASA Astrophysics Data System (ADS)

Chen, Bin; Long, Jiang; Wu, Jun-bao

2011-11-01

In this Letter, we study the spin-3 topologically massive gravity (TMG), paying special attention to its properties at the chiral point. We propose an action describing the higher spin fields coupled to TMG. We discuss the traceless spin-3 fluctuations around the AdS3 vacuum and find that there is an extra local massive mode, besides the left-moving and right-moving boundary massless modes. At the chiral point, such extra mode becomes massless and degenerates with the left-moving mode. We show that at the chiral point the only degrees of freedom in the theory are the boundary right-moving graviton and spin-3 field. We conjecture that spin-3 chiral gravity with generalized Brown-Henneaux boundary condition is holographically dual to 2D chiral CFT with classical W3 algebra and central charge cR = 3 l / G.

Tunnelling with a negative cosmological constant

NASA Astrophysics Data System (ADS)

Gibbons, G. W.

1996-02-01

The point of this paper is to see what light new results in hyperbolic geometry may throw on gravitational entropy and whether gravitational entropy is relevant for the quantum origin of the universe. We introduce some new gravitational instantons which mediate the birth from nothing of closed universes containing wormholes and suggest that they may contribute to the density matrix of the universe. We also discuss the connection between their gravitational action and the topological and volumetric entropies introduced in hyperbolic geometry. These coincide for hyperbolic 4-manifolds, and increase with increasing topological complexity of the 4-manifold. We raise the question of whether the action also increases with the topological complexity of the initial 3-geometry, measured either by its 3-volume or its Matveev complexity. We point out, in distinction to the non-supergravity case, that universes with domains of negative cosmological constant separated by supergravity domain walls cannot be born from nothing. Finally we point out that our wormholes provide examples of the type of Perpetual Motion machines envisaged by Frolov and Novikov.

Killing-Yano Symmetry in Supergravity Theories

NASA Astrophysics Data System (ADS)

Houri, Tsuyoshi

Killing-Yano symmetry has played an important role in the study of black hole physics. In supergravity theories, Killing-Yano symmetry is deformed by the presence of the fluxes which can be identified with skew-symmetric torsion. Therefore, we attempt to classify spacetimes admitting Killing-Yano symmetry with torsion. In particular, the classification problem of metrics admitting a principal Killing-Yano tensor with torsion is discussed.

Holographic complexity and noncommutative gauge theory

NASA Astrophysics Data System (ADS)

Couch, Josiah; Eccles, Stefan; Fischler, Willy; Xiao, Ming-Lei

2018-03-01

We study the holographic complexity of noncommutative field theories. The four-dimensional N=4 noncommutative super Yang-Mills theory with Moyal algebra along two of the spatial directions has a well known holographic dual as a type IIB supergravity theory with a stack of D3 branes and non-trivial NS-NS B fields. We start from this example and find that the late time holographic complexity growth rate, based on the "complexity equals action" conjecture, experiences an enhancement when the non-commutativity is turned on. This enhancement saturates a new limit which is exactly 1/4 larger than the commutative value. We then attempt to give a quantum mechanics explanation of the enhancement. Finite time behavior of the complexity growth rate is also studied. Inspired by the non-trivial result, we move on to more general setup in string theory where we have a stack of D p branes and also turn on the B field. Multiple noncommutative directions are considered in higher p cases.

High Performance Programming Using Explicit Shared Memory Model on the Cray T3D

NASA Technical Reports Server (NTRS)

Saini, Subhash; Simon, Horst D.; Lasinski, T. A. (Technical Monitor)

1994-01-01

The Cray T3D is the first-phase system in Cray Research Inc.'s (CRI) three-phase massively parallel processing program. In this report we describe the architecture of the T3D, as well as the CRAFT (Cray Research Adaptive Fortran) programming model, and contrast it with PVM, which is also supported on the T3D We present some performance data based on the NAS Parallel Benchmarks to illustrate both architectural and software features of the T3D.

3-D parallel program for numerical calculation of gas dynamics problems with heat conductivity on distributed memory computational systems (CS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sofronov, I.D.; Voronin, B.L.; Butnev, O.I.

1997-12-31

The aim of the work performed is to develop a 3D parallel program for numerical calculation of gas dynamics problem with heat conductivity on distributed memory computational systems (CS), satisfying the condition of numerical result independence from the number of processors involved. Two basically different approaches to the structure of massive parallel computations have been developed. The first approach uses the 3D data matrix decomposition reconstructed at temporal cycle and is a development of parallelization algorithms for multiprocessor CS with shareable memory. The second approach is based on using a 3D data matrix decomposition not reconstructed during a temporal cycle.more » The program was developed on 8-processor CS MP-3 made in VNIIEF and was adapted to a massive parallel CS Meiko-2 in LLNL by joint efforts of VNIIEF and LLNL staffs. A large number of numerical experiments has been carried out with different number of processors up to 256 and the efficiency of parallelization has been evaluated in dependence on processor number and their parameters.« less

Loop Integrands for Scattering Amplitudes from the Riemann Sphere

NASA Astrophysics Data System (ADS)

Geyer, Yvonne; Mason, Lionel; Monteiro, Ricardo; Tourkine, Piotr

2015-09-01

The scattering equations on the Riemann sphere give rise to remarkable formulas for tree-level gauge theory and gravity amplitudes. Adamo, Casali, and Skinner conjectured a one-loop formula for supergravity amplitudes based on scattering equations on a torus. We use a residue theorem to transform this into a formula on the Riemann sphere. What emerges is a framework for loop integrands on the Riemann sphere that promises to have a wide application, based on off-shell scattering equations that depend on the loop momentum. We present new formulas, checked explicitly at low points, for supergravity and super-Yang-Mills amplitudes and for n -gon integrands at one loop. Finally, we show that the off-shell scattering equations naturally extend to arbitrary loop order, and we give a proposal for the all-loop integrands for supergravity and planar super-Yang-Mills theory.

Handling Massive Models: Representation, Real-Time Display and Interaction

DTIC Science & Technology

2008-09-16

Published, K. Ward, N. Galoppo, and M. Lin, "Interactive Virtual Hair Salon ", Presence, p. , vol. , (2007). Published, K. Ward, F. Bertails, T.-Y...Detection for Deformable Models using Representative-Triangles", Symposium on Interactive 3D Graphics and Games , p. , vol. , (2008). Published...Interactive 3D Graphics and Games (I3D), p. , vol. , (2008). Published, Brandon Lloyd, Naga K. Govindaraju, Cory Quammen, Steven E. Molnar, Dinesh

Real weights, bound states and duality orbits

NASA Astrophysics Data System (ADS)

Marrani, Alessio; Riccioni, Fabio; Romano, Luca

2016-01-01

We show that the duality orbits of extremal black holes in supergravity theories with symmetric scalar manifolds can be derived by studying the stabilizing subalgebras of suitable representatives, realized as bound states of specific weight vectors of the corresponding representation of the duality symmetry group. The weight vectors always correspond to weights that are real, where the reality properties are derived from the Tits-Satake diagram that identifies the real form of the Lie algebra of the duality symmetry group. Both 𝒩 = 2 magic Maxwell-Einstein supergravities and the semisimple infinite sequences of 𝒩 = 2 and 𝒩 = 4 theories in D = 4 and 5 are considered, and various results, obtained over the years in the literature using different methods, are retrieved. In particular, we show that the stratification of the orbits of these theories occurs because of very specific properties of the representations: in the case of the theory based on the real numbers, whose symmetry group is maximally noncompact and therefore all the weights are real, the stratification is due to the presence of weights of different lengths, while in the other cases it is due to the presence of complex weights.

Sizable electron/neutron electric dipole moment in D 3 /D 7 μ -split supersymmetry

NASA Astrophysics Data System (ADS)

Dhuria, Mansi; Misra, Aalok

2014-10-01

Within the framework of N =1 gauged supergravity, using a phenomenological model that can be obtained locally as a Swiss-cheese Calabi-Yau string-theoretic compactification with a mobile D 3 -brane localized on a nearly special Lagrangian three cycle in the Calabi-Yau and fluxed stacks of wrapped D 7 -branes, and which provides a natural realization of μ -split supersymmetry (SUSY), we show that in addition to getting a significant value of an [electron/neutron (e/n)] electron dipole moment (EDM) at two-loop level, one can obtain a sizable contribution of (e/n) EDM even at one-loop level due to the presence of heavy supersymmetric fermions nearly isospectral with heavy sfermions. Unlike traditional split SUSY models in which the one-loop diagrams do not give significant contribution to the EDM of the electron/neutron because of very heavy sfermions existing as propagators in the loop, we show that one obtains a "healthy" value of the EDM in our model because of the presence of a heavy Higgsino, neutralino/chargino, and gaugino as fermionic propagators in the loops. The independent C P -violating phases are generated from nontrivial distinct phase factors associated with four Wilson line moduli [identified with first-generation leptons and quarks and their S U (2 )L -singlet cousins] as well as the D 3 -brane position moduli (identified with two Higgses), and the same are sufficient to produce overall distinct phase factors corresponding to all possible effective Yukawas as well as effective gauge couplings that we discuss in the context of N =1 gauged supergravity action. However, the complex phases responsible to generate a nonzero EDM at one-loop level mainly appear from an off-diagonal contribution of sfermion as well as Higgs mass matrices at the electroweak scale (EW). In our analysis, we obtain a dominant contribution of the electron/neutron EDM around de/e ≡O (1 0-29) cm from two-loop diagrams involving heavy sfermions and a light Higgs, and de/e ≡O (1 0-32) cm from a one-loop diagram involving a heavy chargino and a light Higgs as propagators in the loop. The neutron EDM gets a dominant contribution of the order dn/e ≡O (1 0-33) cm from the one-loop diagram involving SM-like quarks and Higgs. To justify the possibility of obtaining a large EDM value in the case of a Barr-Zee diagram which involves W± and the Higgs (responsible to generate the nontrivial C P -violating phase) in the two-loop diagrams as discussed by Leigh et al. [Nucl. Phys. B267, 509 (1986)], we provide an analysis of the same in the context of our D 3 /D 7 μ -split SUSY model at the EW scale. By conjecturing that the C P -violating phase can appear from the diagonalization of the Higgs mass matrix obtained in the context of μ -split SUSY, we also get an EDM of the electron/neutron around O (1 0-27) e cm in the case of the two-loop diagram involving W± bosons.

Spectroscopic evidence for bulk-band inversion and three-dimensional massive Dirac fermions in ZrTe5

PubMed Central

Chen, Zhi-Guo; Chen, R. Y.; Zhong, R. D.; Schneeloch, John; Zhang, C.; Huang, Y.; Qu, Fanming; Yu, Rui; Gu, G. D.; Wang, N. L.

2017-01-01

Three-dimensional topological insulators (3D TIs) represent states of quantum matters in which surface states are protected by time-reversal symmetry and an inversion occurs between bulk conduction and valence bands. However, the bulk-band inversion, which is intimately tied to the topologically nontrivial nature of 3D Tis, has rarely been investigated by experiments. Besides, 3D massive Dirac fermions with nearly linear band dispersions were seldom observed in TIs. Recently, a van der Waals crystal, ZrTe5, was theoretically predicted to be a TI. Here, we report an infrared transmission study of a high-mobility [∼33,000 cm2/(V ⋅ s)] multilayer ZrTe5 flake at magnetic fields (B) up to 35 T. Our observation of a linear relationship between the zero-magnetic-field optical absorption and the photon energy, a bandgap of ∼10 meV and a B dependence of the Landau level (LL) transition energies at low magnetic fields demonstrates 3D massive Dirac fermions with nearly linear band dispersions in this system. More importantly, the reemergence of the intra-LL transitions at magnetic fields higher than 17 T reveals the energy cross between the two zeroth LLs, which reflects the inversion between the bulk conduction and valence bands. Our results not only provide spectroscopic evidence for the TI state in ZrTe5 but also open up a new avenue for fundamental studies of Dirac fermions in van der Waals materials. PMID:28096330

Spectroscopic evidence for bulk-band inversion and three-dimensional massive Dirac fermions in ZrTe 5

DOE PAGES

Chen, Zhi -Guo; Chen, R. Y.; Zhong, R. D.; ...

2017-01-17

Three-dimensional topological insulators (3D TIs) represent states of quantum matters in which surface states are protected by time-reversal symmetry and an inversion occurs between bulk conduction and valence bands. However, the bulk-band inversion, which is intimately tied to the topologically nontrivial nature of 3D Tis, has rarely been investigated by experiments. Besides, 3D massive Dirac fermions with nearly linear band dispersions were seldom observed in TIs. Recently, a van der Waals crystal, ZrTe 5, was theoretically predicted to be a TI. Here, we report an infrared transmission study of a high-mobility [~33,000 cm 2/(V • s)] multilayer ZrTe 5 flakemore » at magnetic fields (B) up to 35 T. Our observation of a linear relationship between the zero-magnetic-field optical absorption and the photon energy, a bandgap of ~10 meV and a √B dependence of the Landau level (LL) transition energies at low magnetic fields demonstrates 3D massive Dirac fermions with nearly linear band dispersions in this system. More importantly, the reemergence of the intra-LL transitions at magnetic fields higher than 17 T reveals the energy cross between the two zeroth LLs, which reflects the inversion between the bulk conduction and valence bands. Finally, our results not only provide spectroscopic evidence for the TI state in ZrTe 5 but also open up a new avenue for fundamental studies of Dirac fermions in van der Waals materials.« less

3-D readout-electronics packaging for high-bandwidth massively paralleled imager

DOEpatents

Kwiatkowski, Kris; Lyke, James

2007-12-18

Dense, massively parallel signal processing electronics are co-packaged behind associated sensor pixels. Microchips containing a linear or bilinear arrangement of photo-sensors, together with associated complex electronics, are integrated into a simple 3-D structure (a "mirror cube"). An array of photo-sensitive cells are disposed on a stacked CMOS chip's surface at a 45.degree. angle from light reflecting mirror surfaces formed on a neighboring CMOS chip surface. Image processing electronics are held within the stacked CMOS chip layers. Electrical connections couple each of said stacked CMOS chip layers and a distribution grid, the connections for distributing power and signals to components associated with each stacked CSMO chip layer.

Gravity-oriented microfluidic device for uniform and massive cell spheroid formation

PubMed Central

Lee, Kangsun; Kim, Choong; Young Yang, Jae; Lee, Hun; Ahn, Byungwook; Xu, Linfeng; Yoon Kang, Ji; Oh, Kwang W.

2012-01-01

We propose a simple method for forming massive and uniform three-dimensional (3-D) cell spheroids in a multi-level structured microfluidic device by gravitational force. The concept of orienting the device vertically has allowed spheroid formation, long-term perfusion, and retrieval of the cultured spheroids by user-friendly standard pipetting. We have successfully formed, perfused, and retrieved uniform, size-controllable, well-conditioned spheroids of human embryonic kidney 293 cells (HEK 293) in the gravity-oriented microfluidic device. We expect the proposed method will be a useful tool to study in-vitro 3-D cell models for the proliferation, differentiation, and metabolism of embryoid bodies or tumours. PMID:22662098

Massive Stars

NASA Astrophysics Data System (ADS)

Livio, Mario; Villaver, Eva

2009-11-01

Participants; Preface Mario Livio and Eva Villaver; 1. High-mass star formation by gravitational collapse of massive cores M. R. Krumholz; 2. Observations of massive star formation N. A. Patel; 3. Massive star formation in the Galactic center D. F. Figer; 4. An X-ray tour of massive star-forming regions with Chandra L. K. Townsley; 5. Massive stars: feedback effects in the local universe M. S. Oey and C. J. Clarke; 6. The initial mass function in clusters B. G. Elmegreen; 7. Massive stars and star clusters in the Antennae galaxies B. C. Whitmore; 8. On the binarity of Eta Carinae T. R. Gull; 9. Parameters and winds of hot massive stars R. P. Kudritzki and M. A. Urbaneja; 10. Unraveling the Galaxy to find the first stars J. Tumlinson; 11. Optically observable zero-age main-sequence O stars N. R. Walborn; 12. Metallicity-dependent Wolf-Raynet winds P. A. Crowther; 13. Eruptive mass loss in very massive stars and Population III stars N. Smith; 14. From progenitor to afterlife R. A. Chevalier; 15. Pair-production supernovae: theory and observation E. Scannapieco; 16. Cosmic infrared background and Population III: an overview A. Kashlinsky.

Predicted and Totally Unexpected in the Energy Frontier Opened by LHC

NASA Astrophysics Data System (ADS)

Zichichi, Antonino

2011-01-01

Opening lectures. Sid Coleman and Erice / A. Zichichi. Remembering Sidney Coleman / G.'t Hooft -- Predicted signals at LHC. From extra-dimensions: Multiple branes scenarios and their contenders / I. Antoniadis. Predicted signals at the LHC from technicolor / A. Martin. The one-parameter model at LHC / J. Maxin, E. Mayes and D. V. Nanopoulos. How supercritical string cosmology affects LHC / D. V. Nanopoulos. High scale physics connection to LHC data / P. Nath. Predicted signatures at the LHC from U(I) extensions of the standard model / P. Nath -- Hot theoretical topics. Progress on the ultraviolet finiteness of supergravity / Z. Bern. Status of supersymmetry: Foundations and applications / S. Ferrara and A. Marrani. Quantum gravity from dynamical triangulation / R. Loll. Status of superstring and M-theory / J. H. Schwarz. Some effects of instantons in QCD / G.'t Hooft. Crystalline gravity / G.'t Hooft -- QCD problems. Strongly coupled gauge theories / R. Kenway. Strongly interacting matter at high energy density / L. McLerran. Seminars on specialized topics. The nature and the mass of neutrinos. Majorana vs. Dirac / A. Bettini. The anomalous spin distributions in the nucleon / A. Deshpande. Results from PHENIX at RHIC / M. J. Tannenbaum -- Highlights from laboratories. Highlights from RHIC / Y. Akiba. News from the Gran Sasso Underground Laboratory / E. Coccia. Highlights from TRIUMF / N. S. Lockyer. Highlights from Superkamiokande / M. Koshiba. Highlights from Fermilab / P. J. Oddone. Highlights from IHEP / Y. Wang -- Special sessions for new talents. Fake supergravity and black hole evolution / A. Gnecchi. Track-based improvement in the jet transverse momentum resolution for ATLAS / Z. Marshall. Searches for supersymmetric dark matter with XENON / K. Ni. Running of Newton's constant and quantum gravitational effects / D. Reeb.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tomizawa, Shinya

We show a uniqueness theorem for Kaluza-Klein black holes in the bosonic sector of five-dimensional minimal supergravity. More precisely, under the assumptions of the existence of two commuting axial isometries and a nondegenerate connected event horizon of the cross-section topology S{sup 3}, or lens space, we prove that a stationary charged rotating Kaluza-Klein black hole in five-dimensional minimal supergravity is uniquely characterized by its mass, two independent angular momenta, electric charge, magnetic flux, and nut charge, provided that there exists neither a nut nor a bolt (a bubble) in the domain of outer communication. We also show that under themore » assumptions of the same symmetry, same asymptotics, and the horizon cross section of S{sup 1}xS{sup 2}, a black ring within the same theory--if it exists--is uniquely determined by its dipole charge and rod intervals besides the charges and magnetic flux.« less

Smooth Horizonless Geometries Deep Inside the Black-Hole Regime.

PubMed

Bena, Iosif; Giusto, Stefano; Martinec, Emil J; Russo, Rodolfo; Shigemori, Masaki; Turton, David; Warner, Nicholas P

2016-11-11

We construct the first family of horizonless supergravity solutions that have the same mass, charges, and angular momenta as general supersymmetric rotating D1-D5-P black holes in five dimensions. This family includes solutions with arbitrarily small angular momenta, deep within the regime of quantum numbers and couplings for which a large classical black hole exists. These geometries are well approximated by the black-hole solution, and in particular exhibit the same near-horizon throat. Deep in this throat, the black-hole singularity is resolved into a smooth cap. We also identify the holographically dual states in the N=(4,4) D1-D5 orbifold conformal field theory (CFT). Our solutions are among the states counted by the CFT elliptic genus, and provide examples of smooth microstate geometries within the ensemble of supersymmetric black-hole microstates.

The Dynamics of Massive Starless Cores with ALMA

NASA Astrophysics Data System (ADS)

Tan, Jonathan C.; Kong, Shuo; Butler, Michael J.; Caselli, Paola; Fontani, Francesco

2013-12-01

How do stars that are more massive than the Sun form, and thus how is the stellar initial mass function (IMF) established? Such intermediate- and high-mass stars may be born from relatively massive pre-stellar gas cores, which are more massive than the thermal Jeans mass. The turbulent core accretion model invokes such cores as being in approximate virial equilibrium and in approximate pressure equilibrium with their surrounding clump medium. Their internal pressure is provided by a combination of turbulence and magnetic fields. Alternatively, the competitive accretion model requires strongly sub-virial initial conditions that then lead to extensive fragmentation to the thermal Jeans scale, with intermediate- and high-mass stars later forming by competitive Bondi-Hoyle accretion. To test these models, we have identified four prime examples of massive (~100 M ⊙) clumps from mid-infrared extinction mapping of infrared dark clouds. Fontani et al. found high deuteration fractions of N2H+ in these objects, which are consistent with them being starless. Here we present ALMA observations of these four clumps that probe the N2D+ (3-2) line at 2.''3 resolution. We find six N2D+ cores and determine their dynamical state. Their observed velocity dispersions and sizes are broadly consistent with the predictions of the turbulent core model of self-gravitating, magnetized (with Alfvén Mach number mA ~ 1) and virialized cores that are bounded by the high pressures of their surrounding clumps. However, in the most massive cores, with masses up to ~60 M ⊙, our results suggest that moderately enhanced magnetic fields (so that mA ~= 0.3) may be needed for the structures to be in virial and pressure equilibrium. Magnetically regulated core formation may thus be important in controlling the formation of massive cores, inhibiting their fragmentation, and thus helping to establish the stellar IMF.

Rholography, black holes and Scherk-Schwarz

DOE PAGES

Gaddam, Nava; Gnecchi, Alessandra; Vandoren, Stefan; ...

2015-06-10

We present a construction of a class of near-extremal asymptotically flat black hole solutions in four (or five) dimensional gauged supergravity with R-symmetry gaugings obtained from Scherk-Schwarz reductions on a circle. The entropy of these black holes is counted holographically by the well known MSW (or D1/D5) system, with certain twisted boundary conditions labeled by a twist parameter ρ. Here, we find that the corresponding (0, 4) (or (4, 4)) superconformal algebras are exactly those studied by Schwimmer and Seiberg, using a twist on the outer automorphism group. The interplay between R-symmetries, ρ-algebras and holography leads us to name ourmore » construction “Rholography”.« less

Rholography, black holes and Scherk-Schwarz

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gaddam, Nava; Gnecchi, Alessandra; Vandoren, Stefan

We present a construction of a class of near-extremal asymptotically flat black hole solutions in four (or five) dimensional gauged supergravity with R-symmetry gaugings obtained from Scherk-Schwarz reductions on a circle. The entropy of these black holes is counted holographically by the well known MSW (or D1/D5) system, with certain twisted boundary conditions labeled by a twist parameter ρ. Here, we find that the corresponding (0, 4) (or (4, 4)) superconformal algebras are exactly those studied by Schwimmer and Seiberg, using a twist on the outer automorphism group. The interplay between R-symmetries, ρ-algebras and holography leads us to name ourmore » construction “Rholography”.« less

T-duality, non-geometry and Lie algebroids in heterotic double field theory

NASA Astrophysics Data System (ADS)

Blumenhagen, Ralph; Sun, Rui

2015-02-01

A number of issues in heterotic double field theory are studied. This includes the analysis of the T-dual configurations of a flat constant gauge flux background, which turn out to be non-geometric. Performing a field redefinition to a non-geometric frame, these T-duals take a very simple form reminiscent of the constant Q- and R-flux backgrounds. In addition, it is shown how the analysis of arXiv:1304.2784 generalizes to heterotic generalized geometry. For every field redefinition specified by an O( D, D + n) transformation, the structure of the resulting supergravity action is governed by the differential geometry of a corresponding Lie algebroid.

A deformation of Sasakian structure in the presence of torsion and supergravity solutions

NASA Astrophysics Data System (ADS)

Houri, Tsuyoshi; Takeuchi, Hiroshi; Yasui, Yukinori

2013-07-01

A deformation of Sasakian structure in the presence of totally skew-symmetric torsion is discussed on odd-dimensional manifolds whose metric cones are Kähler with torsion. It is shown that such a geometry inherits similar properties to those of Sasakian geometry. As their example, we present an explicit expression of local metrics. It is also demonstrated that our example of the metrics admits the existence of hidden symmetry described by non-trivial odd-rank generalized closed conformal Killing-Yano tensors. Furthermore, using these metrics as an ansatz, we construct exact solutions in five-dimensional minimal gauged/ungauged supergravity and 11-dimensional supergravity. Finally, the global structures of the solutions are discussed. We obtain regular metrics on compact manifolds in five dimensions, which give natural generalizations of Sasaki-Einstein manifolds Yp, q and La, b, c. We also briefly discuss regular metrics on non-compact manifolds in 11 dimensions.

A superstring field theory for supergravity

NASA Astrophysics Data System (ADS)

Reid-Edwards, R. A.; Riccombeni, D. A.

2017-09-01

A covariant closed superstring field theory, equivalent to classical tendimensional Type II supergravity, is presented. The defining conformal field theory is the ambitwistor string worldsheet theory of Mason and Skinner. This theory is known to reproduce the scattering amplitudes of Cachazo, He and Yuan in which the scattering equations play an important role and the string field theory naturally incorporates these results. We investigate the operator formalism description of the ambitwsitor string and propose an action for the string field theory of the bosonic and supersymmetric theories. The correct linearised gauge symmetries and spacetime actions are explicitly reproduced and evidence is given that the action is correct to all orders. The focus is on the NeveuSchwarz sector and the explicit description of tree level perturbation theory about flat spacetime. Application of the string field theory to general supergravity backgrounds and the inclusion of the Ramond sector are briefly discussed.

Air mobility command passenger reservation center system analysis

DOT National Transportation Integrated Search

2001-03-01

The Department of Defense (DoD) has undergone a massive downsizing in an effort to comply with President Clinton's directive to 'reinvent' government making it more efficient. Therefore, the DoD revamped its $$3.5 billion annual official business tra...

Entanglement entropy of black holes and anti-de Sitter space/conformal-field-theory correspondence.

PubMed

Solodukhin, Sergey N

2006-11-17

A recent proposal by Ryu and Takayanagi for a holographic interpretation of entanglement entropy in conformal field theories dual to supergravity on anti-de Sitter space is generalized to include entanglement entropy of black holes living on the boundary of anti-de Sitter space. The generalized proposal is verified in boundary dimensions d=2 and d=4 for both the uv-divergent and uv-finite terms. In dimension d=4 an expansion of entanglement entropy in terms of size L of the subsystem outside the black hole is considered. A new term in the entropy of dual strongly coupled conformal-field theory, which universally grows as L(2)lnL and is proportional to the value of the obstruction tensor at the black hole horizon, is predicted.

BOOK REVIEW: Supergravity Supergravity

NASA Astrophysics Data System (ADS)

Gregory, Ruth

2013-02-01

Supergravity is an essential ingredient in so many areas of ultra high energy physics, yet it is rarely taught systematically, even at the graduate level. Students most often have to learn along with applying, and must use the now classic older texts. For such core material, it is surprising that there are so few good texts on the subject. It is not necessarily that supergravity is so much more conceptually complex, rather that it is technical and therefore easy for a text to become dry, dense and rather indigestible. This book, written by two experts in the field, is therefore a breath of fresh air. It not only represents a comprehensive modern overview of the subject, but achieves this with clarity, accessibility, and even humour! To paraphrase the authors, if you are not impressed by this book, you should put it down and watch television instead. It starts by reviewing, or overviewing, aspects of field theory, basic supersymmetry and gravity that will be needed for the rest of the book. This first third or so of the book is very condensed, and will not be easy to follow for those who have not encountered the material before. However, the authors acknowledge this and give plenty of suggestions for more pedagogical texts in the relevant areas, thus it does not feel overly brief. The middle section deals with the construction of supergravity, starting with basic N = 1 supergravity in 4 and 11 dimensions and gradually extending the discussion to include matter multiplets. This part of the book systematically builds up understanding and construction of models, before moving on to superconformal methods. The purpose is not to cover all supergravity theories, but to focus on a few examples in detail, and to give sufficient expertise and information for the reader to be able to deal with any other models they might need. The final part of the book deals with applications, and includes two chapters on applications in adS/CFT, which will be of most interest to new students of supergravity. One of the strengths of the book is that it includes many exercises; these are designed to both reinforce the material covered, as well as to elucidate technical issues. They back up the process of learning, and feel part of the narrative rather than a test. If diligently followed, the reader will acquire a great deal of expertise by being guided through these critical learning processes. Another striking feature of the book is its inherent user friendliness. Not only is the layout of the book visually pleasing -- with plenty of margin space to scribble in if so inspired -- but the language of the authors is very accessible, and the gentle humour leavens the material being presented. When asked to work through the manipulations in the previous paragraphs forwards, then backwards, then forwards again, one tends to smile rather than give up! The authors are very aware that this can be challenging material, and have taken every effort to bring it to the reader in an appealing form. To sum up: this is a definitive text on the topic of supergravity. It contains all the relevant material one needs, or signposts clearly where the discussion has been `executive' and one might need to consult more detailed material depending on background. It is rather high level for a beginning graduate student, who has probably not met field theory or general relativity before, but for a more experienced student or researcher, the book is spot on. I found it more like a companion than a teacher, and heartily recommend it to anyone wanting to learn or revisit this fascinating, if technical, topic.

FAST TRACK COMMUNICATION Single-charge rotating black holes in four-dimensional gauged supergravity

NASA Astrophysics Data System (ADS)

Chow, David D. K.

2011-02-01

We consider four-dimensional U(1)4 gauged supergravity, and obtain asymptotically AdS4, non-extremal, charged, rotating black holes with one non-zero U(1) charge. The thermodynamic quantities are computed. We obtain a generalization that includes a NUT parameter. The general solution has a discrete symmetry involving inversion of the rotation parameter, and has a string frame metric that admits a rank-2 Killing-Stäckel tensor.

Entropy of black holes in N=2 supergravity

NASA Astrophysics Data System (ADS)

Chatterjee, A.

2018-07-01

Using the formalism of isolated horizons, we construct space of solutions of asymptotically flat extremal black holes in N=2 pure supergravity in 4 dimensions. We prove that the laws of black hole mechanics hold for these black holes. Further, restricting to constant area phase space, we show that the spherical horizons admit a Chern-Simons theory. Standard way of quantizing this topological theory and counting states confirms that entropy is indeed proportional to the area of horizon.

Symmetry enhancement of extremal horizons in D  =  5 supergravity

NASA Astrophysics Data System (ADS)

Kayani, U.

2018-06-01

We consider the near-horizon geometry of supersymmetric extremal black holes in un-gauged and gauged 5-dimensional supergravity, coupled to abelian vector multiplets. By analyzing the global properties of the Killing spinors, we prove that the near-horizon geometries undergo a supersymmetry enhancement. This follows from a set of generalized Lichnerowicz-type theorems we establish, together with an index theory argument. As a consequence, these solutions always admit a symmetry group.

Deformed D1D5 CFT: A Holographic Probe of Quantum Gravity

NASA Astrophysics Data System (ADS)

Jardine, Ian Theodore

One of the big unsolved questions in gravity research is the black hole information problem. This problem, which pits the unitarity of quantum field theory against smooth classical spacetime, must have a solution in a complete theory of quantum gravity. This thesis will explore aspects of one approach to this problem in the context of string theory. The approach imagines black hole microstates as string theoretic objects. We look at a prototype system, the D1D5 system, and exploit holography to examine the dual conformal field theory (CFT). Specifically, we examine the CFT deformed from the free orbifold point, dual to a very stringy bulk, using a twisted operator that will take us towards the point with the supergravity description. The effects of twisted operators in the CFT are key to understanding physical processes such as emission and thermalization in black hole microstates. We will propose a component twist method for examining the effects of bare twist operators for higher twists in the continuum limit. Our method builds higher twists from simple 2-cycle twists, whose effects are known. We will find that, in this limit, the coefficients describing general states will follow a conjectured general functional form. We then explore the deformed CFT directly by examining operator mixing for untwisted operators. We will exploit the operator product expansion on the covering space, where twist operators of the orbifold are resolved. We use this to examine the mixing of a general supergravity operator, specifically examine the dilaton, and finish with the mixing of a non-supersymmetric candidate operator. We conjecture that this method could be extended to include twisted operators. We will also examine the mixing of the non-supersymmetric candidate operator by examining three point functions. To automate the lengthy and repetitive computations, we wrote a Mathematica package to compute correlation functions and OPEs in the D1D5 CFT. We will explain some of the main functions of this package and how it can be applied to computations. Finally, we will end with a short discussion on future directions.

Charged scalar perturbations on charged black holes in de Rham-Gabadadze-Tolley massive gravity

NASA Astrophysics Data System (ADS)

Burikham, Piyabut; Ponglertsakul, Supakchai; Tannukij, Lunchakorn

2017-12-01

We explore the quasistationary profile of a massive charged scalar field in a class of charged black holes in de Rham-Gabadadze-Tolley (dRGT) massive gravity. We discuss how the linear term in the metric, which is a unique character of the dRGT massive gravity, affects the structure of the spacetime. Numerical calculations of the quasinormal modes are performed for a charged scalar field in the dRGT black hole background. For an asymptotically de Sitter (dS) black hole, an improved asymptotic iteration method is used to obtain the associated quasinormal frequencies. The unstable modes are found for the ℓ=0 case, and their corresponding real parts satisfy the superradiant condition. For ℓ=2 , the results show that all the de Sitter black holes considered here are stable against a small perturbation. For an asymptotically dRGT anti-de Sitter (AdS) black hole, unstable modes are found with the frequency satisfying the superradiant condition. Effects of massive-gravity parameters are discussed. Analytic calculation reveals the unique diffusive nature of quasinormal modes in the massive-gravity model with the linear term. Numerical results confirm the existence of the characteristic diffusive modes in both the dS and AdS cases.

D-Lactic acidosis in a boy with short bowel syndrome.

PubMed Central

Schoorel, E P; Giesberts, M A; Blom, W; van Gelderen, H H

1980-01-01

Metabolic acidosis in a 3-year-old child with short bowel syndrome led to the discovery of massive D-lactic aciduria. After normalisation of the intestinal bacterial flora, D-lactate disappeared together with the acidosis. Dysbacteriosis with excessive production of D-lactate by intestinal bacteria (unidentified) and subsequent absorption explains this unusual cause of metabolic acidosis. PMID:7436446

Eta Carinae: An Astrophysical Laboratory to Study Conditions During the Transition Between a Pseudo-Supernova and a Supernova

NASA Astrophysics Data System (ADS)

McKinnon, Darren; Gull, T. R.; Madura, T.

2014-01-01

A major puzzle in the studies of supernovae is the pseudo-supernova, or the near-supernovae state. It has been found to precede, in timespans ranging from months to years, a number of recently-detected distant supernovae. One explanation of these systems is that a member of a massive binary underwent a near-supernova event shortly before the actual supernova phenomenon. Luckily, we have a nearby massive binary, Eta Carinae, that provides an astrophysical laboratory of a near-analog. The massive, highly-eccentric, colliding-wind binary star system survived a non-terminal stellar explosion in the 1800's, leaving behind the incredible bipolar, 10"x20" Homunculus nebula. Today, the interaction of the binary stellar winds 1") is resolvable by the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space Telescope (HST). Using HST/STIS, several three-dimensional (3D) data cubes (2D spatial, 1D velocity) have been obtained at selected phases during Eta Carinae's 5.54-year orbital cycle. The data cubes were collected by mapping the central 1-2" at 0.05" intervals with a 52"x0.1" aperture. Selected forbidden lines, that form in the colliding wind regions, provide information on electron density of the shocked regions, the ionization by the hot secondary companion of the primary wind and how these regions change with orbital phase. By applying various analysis techniques to these data cubes, we can compare and measure temporal changes due to the interactions between the two massive winds. The observations, when compared to current 3D hydrodynamic models, provide insight on Eta Carinae's recent mass-loss history, important for determining the current and future states of this likely nearby supernova progenitor.

Multimedia Visualisation of Massive Military Datasets (Visualisation multimedia des jeux de donnees militaires massifs)

DTIC Science & Technology

2007-06-01

the Los Angeles Area A-16 Figure A-5 Illustration of the Life Cycle of the Japanese Beetle A-17 Figure B-1 Knowledge Wall B-8 Figure B-2...Structure of World Trade in 1992 C-15 Figure D-1 3D Panorama Cinema at CAVI in Use D-2 Figure D-2 Holobench at CAVI D-2 Figure D-3 Virtual Studio...Illustration of the Life Cycle of the Japanese Beetle. A.6 STEPS IN ESTABLISHING A THEORY OF EFFECTIVE VISUALISATION An established theory generally

Gapped fermionic spectrum from a domain wall in seven dimension

NASA Astrophysics Data System (ADS)

Mukhopadhyay, Subir; Rai, Nishal

2018-05-01

We obtain a domain wall solution in maximally gauged seven dimensional supergravity, which interpolates between two AdS spaces and spontaneously breaks a U (1) symmetry. We analyse frequency dependence of conductivity and find power law behaviour at low frequency. We consider certain fermions of supergravity in the background of this domain wall and compute holographic spectral function of the operators in the dual six dimensional theory. We find fermionic operators involving bosons with non-zero expectation value lead to gapped spectrum.

All symmetric space solutions of eleven-dimensional supergravity

NASA Astrophysics Data System (ADS)

Wulff, Linus

2017-06-01

We find all symmetric space solutions of eleven-dimensional supergravity completing an earlier classification by Figueroa-O’Farrill. They come in two types: AdS solutions and pp-wave solutions. We analyze the supersymmetry conditions and show that out of the 99 AdS geometries the only supersymmetric ones are the well known backgrounds arising as near-horizon limits of (intersecting) branes and preserving 32, 16 or 8 supersymmetries. The general form of the superisometry algebra for symmetric space backgrounds is also derived.

The conformal hyperplet

NASA Astrophysics Data System (ADS)

Faux, Michael

2017-05-01

We introduce a finite off-shell hypermultiplet with no off-shell central charge. This requires 192+192 degrees of freedom, all but 8+8 of which are auxiliary or gauge. In the absence of supergravity, the model has a saddle-point vacuum instability implying ghost-like propagators. These are cured by realizing the model superconformally, such that the erstwhile ghosts are realized as compensators. Gauge fixing these links the physical hypermultiplets to supergravity. This evokes the prospect of realizing 𝒩 = 4 super-Yang-Mills theory off-shell.

Chern-Simons-Antoniadis-Savvidy forms and standard supergravity

NASA Astrophysics Data System (ADS)

Izaurieta, F.; Salgado, P.; Salgado, S.

2017-04-01

In the context of the so called the Chern-Simons-Antoniadis-Savvidy (ChSAS) forms, we use the methods for FDA decomposition in 1-forms to construct a four-dimensional ChSAS supergravity action for the Maxwell superalgebra. On the another hand, we use the Extended Cartan Homotopy Formula to find a method that allows the separation of the ChSAS action into bulk and boundary contributions and permits the splitting of the bulk Lagrangian into pieces that reflect the particular subspace structure of the gauge algebra.

A note on ‘gaugings’ in four spacetime dimensions and electric-magnetic duality

NASA Astrophysics Data System (ADS)

Henneaux, Marc; Julia, Bernard; Lekeu, Victor; Ranjbar, Arash

2018-02-01

The variety of consistent ‘gauging’ deformations of supergravity theories in four dimensions depends on the choice of Lagrangian formulation. One important goal is to get the most general deformations without making hidden assumptions. Ignoring supersymmetry we consider in this paper n v abelian vector potentials in four spacetime dimensions with non-minimal kinetic coupling to n s uncharged (possibly nonlinear) scalar fields. As in the case of extended supergravities, one model may possess different formulations related by \

Cosmological solutions of low-energy heterotic M theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Copeland, Edmund J.; Ellison, James; Roberts, Jonathan

We derive a set of exact cosmological solutions to the D=4, N=1 supergravity description of heterotic M theory. Having identified a new and exact SU(3) Toda model solution, we then apply symmetry transformations to both this solution and to a previously known SU(2) Toda model, in order to derive two further sets of new cosmological solutions. In the symmetry-transformed SU(3) Toda case we find an unusual bouncing motion for the M5 brane, such that this brane can be made to reverse direction part way through its evolution. This bounce occurs purely through the interaction of nonstandard kinetic terms, as theremore » are no explicit potentials in the action. We also present a perturbation calculation which demonstrates that, in a simple static limit, heterotic M theory possesses a scale-invariant isocurvature mode. This mode persists in certain asymptotic limits of all the solutions we have derived, including the bouncing solution.« less

The MASSIVE Survey - V. Spatially resolved stellar angular momentum, velocity dispersion, and higher moments of the 41 most massive local early-type galaxies

NASA Astrophysics Data System (ADS)

Veale, Melanie; Ma, Chung-Pei; Thomas, Jens; Greene, Jenny E.; McConnell, Nicholas J.; Walsh, Jonelle; Ito, Jennifer; Blakeslee, John P.; Janish, Ryan

2017-01-01

We present spatially resolved two-dimensional stellar kinematics for the 41 most massive early-type galaxies (ETGs; MK ≲ -25.7 mag, stellar mass M* ≳ 1011.8 M⊙) of the volume-limited (D < 108 Mpc) MASSIVE survey. For each galaxy, we obtain high-quality spectra in the wavelength range of 3650-5850 Å from the 246-fibre Mitchell integral-field spectrograph at McDonald Observatory, covering a 107 arcsec × 107 arcsec field of view (often reaching 2 to 3 effective radii). We measure the 2D spatial distribution of each galaxy's angular momentum (λ and fast or slow rotator status), velocity dispersion (σ), and higher order non-Gaussian velocity features (Gauss-Hermite moments h3 to h6). Our sample contains a high fraction (˜80 per cent) of slow and non-rotators with λ ≲ 0.2. When combined with the lower mass ETGs in the ATLAS3D survey, we find the fraction of slow rotators to increase dramatically with galaxy mass, reaching ˜50 per cent at MK ˜ -25.5 mag and ˜90 per cent at MK ≲ -26 mag. All of our fast rotators show a clear anticorrelation between h3 and V/σ, and the slope of the anticorrelation is steeper in more round galaxies. The radial profiles of σ show a clear luminosity and environmental dependence: the 12 most luminous galaxies in our sample (MK ≲ -26 mag) are all brightest cluster/group galaxies (except NGC 4874) and all have rising or nearly flat σ profiles, whereas five of the seven `isolated' galaxies are all fainter than MK = -25.8 mag and have falling σ. All of our galaxies have positive average h4; the most luminous galaxies have average h4 ˜ 0.05, while less luminous galaxies have a range of values between 0 and 0.05. Most of our galaxies show positive radial gradients in h4, and those galaxies also tend to have rising σ profiles. We discuss the implications for the relationship among dynamical mass, σ, h4, and velocity anisotropy for these massive galaxies.

Relativistic space-charge-limited current for massive Dirac fermions

NASA Astrophysics Data System (ADS)

Ang, Y. S.; Zubair, M.; Ang, L. K.

2017-04-01

A theory of relativistic space-charge-limited current (SCLC) is formulated to determine the SCLC scaling, J ∝Vα/Lβ , for a finite band-gap Dirac material of length L biased under a voltage V . In one-dimensional (1D) bulk geometry, our model allows (α ,β ) to vary from (2,3) for the nonrelativistic model in traditional solids to (3/2,2) for the ultrarelativistic model of massless Dirac fermions. For 2D thin-film geometry we obtain α =β , which varies between 2 and 3/2, respectively, at the nonrelativistic and ultrarelativistic limits. We further provide rigorous proof based on a Green's-function approach that for a uniform SCLC model described by carrier-density-dependent mobility, the scaling relations of the 1D bulk model can be directly mapped into the case of 2D thin film for any contact geometries. Our simplified approach provides a convenient tool to obtain the 2D thin-film SCLC scaling relations without the need of explicitly solving the complicated 2D problems. Finally, this work clarifies the inconsistency in using the traditional SCLC models to explain the experimental measurement of a 2D Dirac semiconductor. We conclude that the voltage scaling 3 /2 <α <2 is a distinct signature of massive Dirac fermions in a Dirac semiconductor and is in agreement with experimental SCLC measurements in MoS2.

No hair theorem in quasi-dilaton massive gravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, De-Jun; Zhou, Shuang-Yong

We investigate the static, spherically symmetric black hole solutions in the quasi-dilaton model and its generalizations, which are scalar extended dRGT massive gravity with a shift symmetry. We show that, unlike generic scalar extended massive gravity models, these theories do not admit static, spherically symmetric black hole solutions until the theory parameters in the dRGT potential are fine-tuned. When fine-tuned, the geometry of the static, spherically symmetric black hole is necessarily that of general relativity and the quasi-dilaton field is constant across the spacetime. The fine-tuning and the no hair theorem apply to black holes with flat, anti-de Sitter ormore » de Sitter asymptotics. (C) 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP(3).« less

No hair theorem in quasi-dilaton massive gravity

DOE PAGES

Wu, De-Jun; Zhou, Shuang-Yong

2016-04-11

We investigate the static, spherically symmetric black hole solutions in the quasi-dilaton model and its generalizations, which are scalar extended dRGT massive gravity with a shift symmetry. We show that, unlike generic scalar extended massive gravity models, these theories do not admit static, spherically symmetric black hole solutions until the theory parameters in the dRGT potential are fine-tuned. When fine-tuned, the geometry of the static, spherically symmetric black hole is necessarily that of general relativity and the quasi-dilaton field is constant across the spacetime. The fine-tuning and the no hair theorem apply to black holes with flat, anti-de Sitter ormore » de Sitter asymptotics. (C) 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP(3).« less

First results from the IllustrisTNG simulations: the stellar mass content of groups and clusters of galaxies

NASA Astrophysics Data System (ADS)

Pillepich, Annalisa; Nelson, Dylan; Hernquist, Lars; Springel, Volker; Pakmor, Rüdiger; Torrey, Paul; Weinberger, Rainer; Genel, Shy; Naiman, Jill P.; Marinacci, Federico; Vogelsberger, Mark

2018-03-01

The IllustrisTNG project is a new suite of cosmological magnetohydrodynamical simulations of galaxy formation performed with the AREPO code and updated models for feedback physics. Here, we introduce the first two simulations of the series, TNG100 and TNG300, and quantify the stellar mass content of about 4000 massive galaxy groups and clusters (1013 ≤ M200c/M⊙ ≤ 1015) at recent times (z ≤ 1). The richest clusters have half of their total stellar mass bound to satellite galaxies, with the other half being associated with the central galaxy and the diffuse intracluster light. Haloes more massive than about 5 × 1014 M⊙ have more diffuse stellar mass outside 100 kpc than within 100 kpc, with power-law slopes of the radial mass density distribution as shallow as the dark matter's ( - 3.5 ≲ α3D ≲ -3). Total halo mass is a very good predictor of stellar mass, and vice versa: at z = 0, the 3D stellar mass measured within 30 kpc scales as ∝(M500c)0.49 with a ˜0.12 dex scatter. This is possibly too steep in comparison to the available observational constraints, even though the abundance of The Next Generation less-massive galaxies ( ≲ 1011 M⊙ in stars) is in good agreement with the measured galaxy stellar mass functions at recent epochs. The 3D sizes of massive galaxies fall too on a tight (˜0.16 dex scatter) power-law relation with halo mass, with r^stars_0.5 ∝ (M_200c)^{0.53}. Even more fundamentally, halo mass alone is a good predictor for the whole stellar mass profiles beyond the inner few kiloparsecs, and we show how on average these can be precisely recovered given a single-mass measurement of the galaxy or its halo.

A black hole quartet: New solutions and applications to string theory

NASA Astrophysics Data System (ADS)

Padi, Megha

In this thesis, we study a zoo of black hole solutions which help us connect string theory to the universe we live in. The intuition for how to attack fundamental problems can often be found in a toy model. In Chapter 2, we show that three-dimensional topologically massive gravity with a negative cosmological constant -ℓ -2 and coupling constant has "warped AdS3" solutions with SL(2, R ) x U(1) isometry. For muℓ > 3, we show that certain discrete quotients of warped AdS3 lead to black holes. Their thermodynamics is consistent with the existence of a holographic dual CFT with central charges cR = 15mℓ 2+81Gmm ℓ2+27 and cL = 12mℓ 2Gmm ℓ2+27 . The entropy of many supersymmetric black holes have been accounted for, but more realistic non-supersymmetric black holes have been largely overlooked. In Chapter 3, we derive new single-centered and multi-centered non-BPS black hole solutions for several four dimensional models which, after Kaluza-Klein reduction, admit a description in terms of a sigma model with symmetric target space. In particular, we provide the exact solution with generic charges and asymptotic moduli in N=2 supergravity coupled to one vector multiplet. As it stands, the current formulation of string theory allows for an extremely large number of possible solutions (or vacua). We first analyze this landscape by looking for universal characteristics. In Chapter 4, we provide evidence for the conjecture that gravity is always the weakest force in any string compactification. We show that, in several examples arising in string theory, higher-derivative corrections always make extremal non-supersymmetric black holes lighter than the classical bound M/Q = 1. In Chapter 5, we construct novel black hole bound states, called orientiholes, that are T-dual to IIB orientifold compactifications. The gravitational entropy of such orientiholes provides an "experimental" estimate of the number of vacua in various sectors of the IIB landscape. Furthermore, basic physical properties of orientiholes map to (sometimes subtle) microscopic features, thus providing a useful alternative viewpoint on a number of issues arising in D-brane model building. We also suggest a relation to the topological string analogous to the OSV conjecture.

CERN Winter School on Supergravity, Strings, and Gauge Theory 2010

ScienceCinema

McAllister, Liam

2018-05-14

The CERN Winter School on Supergravity, Strings, and Gauge Theory is the analytic continuation of the yearly training school of the former EC-RTN string network "Constituents, Fundamental Forces and Symmetries of the Universe". The 2010 edition of the school is supported and organized by the CERN Theory Divison, and will take place from Monday January 25 to Friday January 29, at CERN. As its predecessors, this school is meant primarily for training of doctoral students and young postdoctoral researchers in recent developments in theoretical high-energy physics and string theory. The programme of the school will consist of five series of pedagogical lectures, complemented by tutorial discussion sessions in the afternoons. Previous schools in this series were organized in 2005 at SISSA in Trieste, and in 2006, 2007, 2008, and 2009 at CERN, Geneva. Other similar schools have been organized in the past by the former related RTN network "The Quantum Structure of Spacetime and the Geometric Nature of Fundamental Interactions". This edition of the school is not funded by the European Union. The school is funded by the CERN Theory Division, and the Arnold Sommerfeld Center at Ludwig-Maximilians University of Munich. Scientific committee: M. Gaberdiel, D. Luest, A. Sevrin, J. Simon, K. Stelle, S. Theisen, A. Uranga, A. Van Proeyen, E. Verlinde Local organizers: A. Uranga, J. Walcher

CERN Winter School on Supergravity, Strings, and Gauge Theory 2010

ScienceCinema

None

2018-05-22

The CERN Winter School on Supergravity, Strings, and Gauge Theory is the analytic continuation of the yearly training school of the former EC-RTN string network "Constituents, Fundamental Forces and Symmetries of the Universe". The 2010 edition of the school is supported and organized by the CERN Theory Divison, and will take place from Monday January 25 to Friday January 29, at CERN. As its predecessors, this school is meant primarily for training of doctoral students and young postdoctoral researchers in recent developments in theoretical high-energy physics and string theory. The programme of the school will consist of five series of pedagogical lectures, complemented by tutorial discussion sessions in the afternoons.Previous schools in this series were organized in 2005 at SISSA in Trieste, and in 2006, 2007, 2008, and 2009 at CERN, Geneva. Other similar schools have been organized in the past by the former related RTN network "The Quantum Structure of Spacetime and the Geometric Nature of Fundamental Interactions". This edition of the school is not funded by the European Union. The school is funded by the CERN Theory Division, and the Arnold Sommerfeld Center at Ludwig-Maximilians University of Munich. Scientific committee: M. Gaberdiel, D. Luest, A. Sevrin, J. Simon, K. Stelle, S. Theisen, A. Uranga, A. Van Proeyen, E. Verlinde Local organizers: A. Uranga, J. Walcher

CERN Winter School on Supergravity, Strings, and Gauge Theory 2010

ScienceCinema

None

2018-06-28

The CERN Winter School on Supergravity, Strings, and Gauge Theory is the analytic continuation of the yearly training school of the former EC-RTN string network "Constituents, Fundamental Forces and Symmetries of the Universe". The 2010 edition of the school is supported and organized by the CERN Theory Divison, and will take place from Monday January 25 to Friday January 29, at CERN. As its predecessors, this school is meant primarily for training of doctoral students and young postdoctoral researchers in recent developments in theoretical high-energy physics and string theory. The programme of the school will consist of five series of pedagogical lectures, complemented by tutorial discussion sessions in the afternoons. Previous schools in this series were organized in 2005 at SISSA in Trieste, and in 2006, 2007, 2008, and 2009 at CERN, Geneva. Other similar schools have been organized in the past by the former related RTN network "The Quantum Structure of Spacetime and the Geometric Nature of Fundamental Interactions". This edition of the school is not funded by the European Union. The school is funded by the CERN Theory Division, and the Arnold Sommerfeld Center at Ludwig-Maximilians University of Munich. Scientific committee: M. Gaberdiel, D. Luest, A. Sevrin, J. Simon, K. Stelle, S. Theisen, A. Uranga, A. Van Proeyen, E. Verlinde Local organizers: A. Uranga, J. Walcher

CERN Winter School on Supergravity, Strings, and Gauge Theory 2010

ScienceCinema

None

2018-05-23

The CERN Winter School on Supergravity, Strings, and Gauge Theory is the analytic continuation of the yearly training school of the former EC-RTN string network "Constituents, Fundamental Forces and Symmetries of the Universe". The 2010 edition of the school is supported and organized by the CERN Theory Divison, and will take place from Monday January 25 to Friday January 29, at CERN. As its predecessors, this school is meant primarily for training of doctoral students and young postdoctoral researchers in recent developments in theoretical high-energy physics and string theory. The programme of the school will consist of five series of pedagogical lectures, complemented by tutorial discussion sessions in the afternoons. Previous schools in this series were organized in 2005 at SISSA in Trieste, and in 2006, 2007, 2008, and 2009 at CERN, Geneva. Other similar schools have been organized in the past by the former related RTN network "The Quantum Structure of Spacetime and the Geometric Nature of Fundamental Interactions". This edition of the school is not funded by the European Union. The school is funded by the CERN Theory Division, and the Arnold Sommerfeld Center at Ludwig-Maximilians University of Munich. Scientific committee: M. Gaberdiel, D. Luest, A. Sevrin, J. Simon, K. Stelle, S. Theisen, A. Uranga, A. Van Proeyen, E. Verlinde Local organizers: A. Uranga, J. Walcher

CERN Winter School on Supergravity, Strings, and Gauge Theory 2010

ScienceCinema

None

2017-12-09

The CERN Winter School on Supergravity, Strings, and Gauge Theory is the analytic continuation of the yearly training school of the former EC-RTN string network "Constituents, Fundamental Forces and Symmetries of the Universe". The 2010 edition of the school is supported and organized by the CERN Theory Divison, and will take place from Monday January 25 to Friday January 29, at CERN. As its predecessors, this school is meant primarily for training of doctoral students and young postdoctoral researchers in recent developments in theoretical high-energy physics and string theory. The programme of the school will consist of five series of pedagogical lectures, complemented by tutorial discussion sessions in the afternoons. Previous schools in this series were organized in 2005 at SISSA in Trieste, and in 2006, 2007, 2008, and 2009 at CERN, Geneva. Other similar schools have been organized in the past by the former related RTN network "The Quantum Structure of Spacetime and the Geometric Nature of Fundamental Interactions". This edition of the school is not funded by the European Union. The school is funded by the CERN Theory Division, and the Arnold Sommerfeld Center at Ludwig-Maximilians University of Munich. Scientific committee: M. Gaberdiel, D. Luest, A. Sevrin, J. Simon, K. Stelle, S. Theisen, A. Uranga, A. Van Proeyen, E. Verlinde Local organizers: A. Uranga, J. Walcher

CERN Winter School on Supergravity, Strings, and Gauge Theory 2010

ScienceCinema

McAllister, Liam

2018-05-24

The CERN Winter School on Supergravity, Strings, and Gauge Theory is the analytic continuation of the yearly training school of the former EC-RTN string network "Constituents, Fundamental Forces and Symmetries of the Universe";. The 2010 edition of the school is supported and organized by the CERN Theory Divison, and will take place from Monday January 25 to Friday January 29, at CERN. As its predecessors, this school is meant primarily for training of doctoral students and young postdoctoral researchers in recent developments in theoretical high-energy physics and string theory. The programme of the school will consist of five series of pedagogical lectures, complemented by tutorial discussion sessions in the afternoons. Previous schools in this series were organized in 2005 at SISSA in Trieste, and in 2006, 2007, 2008, and 2009 at CERN, Geneva. Other similar schools have been organized in the past by the former related RTN network "The Quantum Structure of Spacetime and the Geometric Nature of Fundamental Interactions".This edition of the school is not funded by the European Union. The school is funded by the CERN Theory Division, and the Arnold Sommerfeld Center at Ludwig-Maximilians University of Munich. Scientific committee: M. Gaberdiel, D. Luest, A. Sevrin, J. Simon, K. Stelle, S. Theisen, A. Uranga, A. Van Proeyen, E. Verlinde. Local organizers: A. Uranga, J. Walcher

CERN Winter School on Supergravity, Strings, and Gauge Theory 2010

ScienceCinema

Sen, Ashoke

2018-04-27

The CERN Winter School on Supergravity, Strings, and Gauge Theory is the analytic continuation of the yearly training school of the former EC-RTN string network "Constituents, Fundamental Forces and Symmetries of the Universe". The 2010 edition of the school is supported and organized by the CERN Theory Divison, and will take place from Monday January 25 to Friday January 29, at CERN. As its predecessors, this school is meant primarily for training of doctoral students and young postdoctoral researchers in recent developments in theoretical high-energy physics and string theory. The programme of the school will consist of five series of pedagogical lectures, complemented by tutorial discussion sessions in the afternoons. Previous schools in this series were organized in 2005 at SISSA in Trieste, and in 2006, 2007, 2008, and 2009 at CERN, Geneva. Other similar schools have been organized in the past by the former related RTN network". The Quantum Structure of Spacetime and the Geometric Nature of Fundamental Interactions". This edition of the school is not funded by the European Union. The school is funded by the CERN Theory Division, and the Arnold Sommerfeld Center at Ludwig-Maximilians University of Munich. Scientific committee: M. Gaberdiel, D. Luest, A. Sevrin, J. Simon, K. Stelle, S. Theisen, A. Uranga, A. Van Proeyen, E. Verlinde Local organizers: A. Uranga, J. Walcher.

CERN Winter School on Supergravity, Strings, and Gauge Theory 2010

ScienceCinema

None

2018-05-23

The CERN Winter School on Supergravity, Strings, and Gauge Theory is the analytic continuation of the yearly training school of the former EC-RTN string network "Constituents, Fundamental Forces and Symmetries of the Universe";. The 2010 edition of the school is supported and organized by the CERN Theory Divison, and will take place from Monday January 25 to Friday January 29, at CERN. As its predecessors, this school is meant primarily for training of doctoral students and young postdoctoral researchers in recent developments in theoretical high-energy physics and string theory. The programme of the school will consist of five series of pedagogical lectures, complemented by tutorial discussion sessions in the afternoons. Previous schools in this series were organized in 2005 at SISSA in Trieste, and in 2006, 2007, 2008, and 2009 at CERN, Geneva. Other similar schools have been organized in the past by the former related RTN network "The Quantum Structure of Spacetime and the Geometric Nature of Fundamental Interactions". This edition of the school is not funded by the European Union. The school is funded by the CERN Theory Division, and the Arnold Sommerfeld Center at Ludwig-Maximilians University of Munich. Scientific committee: M. Gaberdiel, D. Luest, A. Sevrin, J. Simon, K. Stelle, S. Theisen, A. Uranga, A. Van Proeyen, E. Verlinde Local organizers: A. Uranga, J. Walcher

Manifesting enhanced cancellations in supergravity: integrands versus integrals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bern, Zvi; Enciso, Michael; Parra-Martinez, Julio

2017-05-25

We have found examples of `enhanced ultraviolet cancellations' with no known standard-symmetry explanation in a variety of supergravity theories. Furthermore, by examining one- and two-loop examples in four- and five-dimensional half-maximal supergravity, we argue that enhanced cancellations in general cannot be exhibited prior to integration. In light of this, we explore reorganizations of integrands into parts that are manifestly finite and parts that have poor power counting but integrate to zero due to integral identities. At two loops we find that in the large loop-momentum limit the required integral identities follow from Lorentz and SL(2) relabeling symmetry. We carry outmore » a nontrivial check at four loops showing that the identities generated in this way are a complete set. We propose that at L loops the combination of Lorentz and SL(L) symmetry is sufficient for displaying enhanced cancellations when they happen, whenever the theory is known to be ultraviolet finite up to (L - 1) loops.« less

Eliminating the η-problem in SUGRA hybrid inflation with vector backreaction

NASA Astrophysics Data System (ADS)

Dimopoulos, Konstantinos; Lazarides, George; Wagstaff, Jacques M.

2012-02-01

It is shown that, when the inflaton field modulates the gauge kinetic function of the gauge fields in supergravity realisations of inflation, the dynamic backreaction leads to a new inflationary attractor solution, in which the inflaton's variation suffers additional impedance. As a result, slow-roll inflation can naturally occur along directions of the scalar potential which would be too steep and curved to support it otherwise. This provides a generic solution to the infamous eta-problem of inflation in supergravity. Moreover, it is shown that, in the new inflationary attractor, the spectral index of the generated curvature perturbations is kept mildly red despite eta of order unity. The above findings are applied to a model of hybrid inflation in supergravity with a generic Kähler potential. The spectral index of the generated curvature perturbations is found to be 0.97-0.98, in excellent agreement with observations. The gauge field can play the role of the vector curvaton after inflation but observable statistical anisotropy requires substantial tuning of the gauge coupling.

NGC 5626: a massive fast rotator with a twist

NASA Astrophysics Data System (ADS)

Viaene, S.; Sarzi, M.; Baes, M.; Puerari, I.

2018-02-01

We present a kinematic analysis of the dust-lane elliptical NGC 5626 based on MUSE observations. These data allow us to robustly classify this galaxy as a fast rotator and to infer a virial mass of 1011.7 M⊙, making it one of the most massive fast rotators known. In addition, the depth and extent of the MUSE data reveal a strong kinematic twist in the stellar velocity field (by up to 45° beyond 1.5Re). A comparison with the ATLAS3D sample underlines the rareness of this system, although we show that such a large-scale kinematic twist could have been missed by the ATLAS3D data due to the limited spatial sampling of this survey (typically extending to 0.6Re for massive early-type galaxies). MUSE thus has the potential to unveil more examples of this type of galaxies. We discuss the environment and possible formation history of NGC 5626 and finally argue how a merger between the Milky Way and Andromeda could produce a galaxy of the same class as NGC 5626.

Two-dimensional Schrödinger symmetry and three-dimensional breathers and Kelvin-ripple complexes as quasi-massive-Nambu-Goldstone modes

NASA Astrophysics Data System (ADS)

Takahashi, Daisuke A.; Ohashi, Keisuke; Fujimori, Toshiaki; Nitta, Muneto

2017-08-01

Bose-Einstein condensates (BECs) confined in a two-dimensional (2D) harmonic trap are known to possess a hidden 2D Schrödinger symmetry, that is, the Schrödinger symmetry modified by a trapping potential. Spontaneous breaking of this symmetry gives rise to a breathing motion of the BEC, whose oscillation frequency is robustly determined by the strength of the harmonic trap. In this paper, we demonstrate that the concept of the 2D Schrödinger symmetry can be applied to predict the nature of three-dimensional (3D) collective modes propagating along a condensate confined in an elongated trap. We find three kinds of collective modes whose existence is robustly ensured by the Schrödinger symmetry, which are physically interpreted as one breather mode and two Kelvin-ripple complex modes, i.e., composite modes in which the vortex core and the condensate surface oscillate interactively. We provide analytical expressions for the dispersion relations (energy-momentum relation) of these modes using the Bogoliubov theory [D. A. Takahashi and M. Nitta, Ann. Phys. 354, 101 (2015), 10.1016/j.aop.2014.12.009]. Furthermore, we point out that these modes can be interpreted as "quasi-massive-Nambu-Goldstone (NG) modes", that is, they have the properties of both quasi-NG and massive NG modes: quasi-NG modes appear when a symmetry of a part of a Lagrangian, which is not a symmetry of a full Lagrangian, is spontaneously broken, while massive NG modes appear when a modified symmetry is spontaneously broken.

Eta Carinae: An Observational Testbed for 3-D Interacting Wind Modeling

NASA Technical Reports Server (NTRS)

Gull, Theodore; Madura, Tom; Groh, Jose; Corcoran, Mike; Owocki, Stan

2011-01-01

Eta Car, with its very massive interacting winds, provides shocked arc-like structures dense enough to trace in forbidden emission lines out to 0.7" (1700 AU). As the massive binary is in a very elliptical orbit (e approx. 0.9), the spatial and velocity structures of these winds change over the 5.54 year period. We can tract ionization structures by several forbidden emission lines. With the addition of radiative transfer on a time-step frame-by-frame basis, we are learning much new information on the ballistic structures, and may gain insight on how molecules and dust might form in these very massive systems.

Bosonization of fermions coupled to topologically massive gravity

NASA Astrophysics Data System (ADS)

Fradkin, Eduardo; Moreno, Enrique F.; Schaposnik, Fidel A.

2014-03-01

We establish a duality between massive fermions coupled to topologically massive gravity (TMG) in d=3 space-time dimensions and a purely gravity theory which also will turn out to be a TMG theory but with different parameters: the original graviton mass in the TMG theory coupled to fermions picks up a contribution from fermion bosonization. We obtain explicit bosonization rules for the fermionic currents and for the energy-momentum tensor showing that the identifications do not depend explicitly on the parameters of the theory. These results are the gravitational analog of the results for 2+1 Abelian and non-Abelian bosonization in flat space-time.

Analytical expression for a class of spherically symmetric solutions in Lorentz-breaking massive gravity

NASA Astrophysics Data System (ADS)

Li, Ping; Li, Xin-zhou; Xi, Ping

2016-06-01

We present a detailed study of the spherically symmetric solutions in Lorentz-breaking massive gravity. There is an undetermined function { F }(X,{w}1,{w}2,{w}3) in the action of Stückelberg fields {S}φ ={{{Λ }}}4\\int {{{d}}}4x\\sqrt{-g}{ F }, which should be resolved through physical means. In general relativity, the spherically symmetric solution to the Einstein equation is a benchmark and its massive deformation also plays a crucial role in Lorentz-breaking massive gravity. { F } will satisfy the constraint equation {T}01=0 from the spherically symmetric Einstein tensor {G}01=0, if we maintain that any reasonable physical theory should possess the spherically symmetric solutions. The Stückelberg field {φ }i is taken as a ‘hedgehog’ configuration {φ }i=φ (r){x}i/r, whose stability is guaranteed by the topological one. Under this ansätz, {T}01=0 is reduced to d{ F }=0. The functions { F } for d{ F }=0 form a commutative ring {R}{ F }. We obtain an expression of the solution to the functional differential equation with spherical symmetry if { F }\\in {R}{ F }. If { F }\\in {R}{ F } and \\partial { F }/\\partial X=0, the functions { F } form a subring {S}{ F }\\subset {R}{ F }. We show that the metric is Schwarzschild, Schwarzschild-AdS or Schwarzschild-dS if { F }\\in {S}{ F }. When { F }\\in {R}{ F } but { F }\

Universality of multi-field α-attractors

NASA Astrophysics Data System (ADS)

Achúcarro, Ana; Kallosh, Renata; Linde, Andrei; Wang, Dong-Gang; Welling, Yvette

2018-04-01

We study a particular version of the theory of cosmological α-attractors with α=1/3, in which both the dilaton (inflaton) field and the axion field are light during inflation. The kinetic terms in this theory originate from maximal Script N=4 superconformal symmetry and from maximal Script N=8 supergravity. We show that because of the underlying hyperbolic geometry of the moduli space in this theory, it exhibits double attractor behavior: their cosmological predictions are stable not only with respect to significant modifications of the dilaton potential, but also with respect to significant modifications of the axion potential: nssimeq1‑2/N, rsimeq4/N2. We also show that the universality of predictions extends to other values of α lesssim Script O(1) with general two-field potentials that may or may not have an embedding in supergravity. Our results support the idea that inflation involving multiple, not stabilized, light fields on a hyperbolic manifold may be compatible with current observational constraints for a broad class of potentials.

R4 terms in supergravities via T -duality constraint

NASA Astrophysics Data System (ADS)

Razaghian, Hamid; Garousi, Mohammad R.

2018-05-01

It has been speculated in the literature that the effective actions of string theories at any order of α' should be invariant under the Buscher rules plus their higher covariant-derivative corrections. This may be used as a constraint to find effective actions at any order of α', in particular, the metric, the B -field, and the dilaton couplings in supergravities at order α'3 up to an overall factor. For the simple case of zero B -field and diagonal metric in which we have done the calculations explicitly, we have found that the constraint fixes almost all of the seven independent Riemann curvature couplings. There is only one term which is not fixed, because when metric is diagonal, the reduction of two R4 terms becomes identical. The Riemann curvature couplings that the T -duality constraint produces for both type II and heterotic theories are fully consistent with the existing couplings in the literature which have been found by the S-matrix and by the sigma-model approaches.

Spontaneous breaking of scale invariance in a D = 3 U(N ) model with Chern-Simons gauge fields

DOE PAGES

Bardeen, William A.; Moshe, Moshe

2014-06-18

We study spontaneous breaking of scale invariance in the large N limit of three dimensional U(N ) κ Chern-Simons theories coupled to a scalar field in the fundamental representation. When a λ 6 ( Ø † · Ø) 3 self interaction term is added to the action we find a massive phase at a certain critical value for a combination of the λ(6) and ’t Hooft’s λ = N/κ couplings. This model attracted recent attention since at finite κ it contains a singlet sector which is conjectured to be dual to Vasiliev’s higher spin gravity on AdS 4. Our papermore » concentrates on the massive phase of the 3d boundary theory. We discuss the advantage of introducing masses in the boundary theory through spontaneous breaking of scale invariance.« less

Non-local Effects of Conformal Anomaly

NASA Astrophysics Data System (ADS)

Meissner, Krzysztof A.; Nicolai, Hermann

2018-03-01

It is shown that the nonlocal anomalous effective actions corresponding to the quantum breaking of the conformal symmetry can lead to observable modifications of Einstein's equations. The fact that Einstein's general relativity is in perfect agreement with all observations including cosmological or recently observed gravitational waves imposes strong restrictions on the field content of possible extensions of Einstein's theory: all viable theories should have vanishing conformal anomalies. It is shown that a complete cancellation of conformal anomalies in D=4 for both the C^2 invariant and the Euler (Gauss-Bonnet) invariant can only be achieved for N-extended supergravity multiplets with N ≥ 5.

Impurity mixing and radiation asymmetry in massive gas injection simulations of DIII-D

DOE Office of Scientific and Technical Information (OSTI.GOV)

Izzo, V. A.

Simulations of neon massive gas injection into DIII-D are performed with the 3D MHD code NIMROD. The poloidal and toroidal distribution of the impurity source is varied. This report will focus on the effects of the source variation on impurity mixing and radiated power asymmetry. Even toroidally symmetric impurity injection is found to produce asymmetric radiated power due to asymmetric convective heat flux produced by the 1/1 mode. When the gas source is toroidally localized, the phase relationship between the mode and the source location is important, affecting both radiation peaking and impurity mixing. Under certain circumstances, a single, localizedmore » gas jet could produce better radiation symmetry during the disruption thermal quench than evenly distributed impurities.« less

Modeling populations of rotationally mixed massive stars

NASA Astrophysics Data System (ADS)

Brott, I.

2011-02-01

Massive stars can be considered as cosmic engines. With their high luminosities, strong stellar winds and violent deaths they drive the evolution of galaxies through-out the history of the universe. Despite the importance of massive stars, their evolution is still poorly understood. Two major issues have plagued evolutionary models of massive stars until today: mixing and mass loss On the main sequence, the effects of mass loss remain limited in the considered mass and metallicity range, this thesis concentrates on the role of mixing in massive stars. This thesis approaches this problem just on the cross road between observations and simulations. The main question: Do evolutionary models of single stars, accounting for the effects of rotation, reproduce the observed properties of real stars. In particular we are interested if the evolutionary models can reproduce the surface abundance changes during the main-sequence phase. To constrain our models we build a population synthesis model for the sample of the VLT-FLAMES Survey of Massive stars, for which star-formation history and rotational velocity distribution are well constrained. We consider the four main regions of the Hunter diagram. Nitrogen un-enriched slow rotators and nitrogen enriched fast rotators that are predicted by theory. Nitrogen enriched slow rotators and nitrogen unenriched fast rotators that are not predicted by our model. We conclude that currently these comparisons are not sufficient to verify the theory of rotational mixing. Physical processes in addition to rotational mixing appear necessary to explain the stars in the later two regions. The chapters of this Thesis have been published in the following Journals: Ch. 2: ``Rotating Massive Main-Sequence Stars I: Grids of Evolutionary Models and Isochrones'', I. Brott, S. E. de Mink, M. Cantiello, N. Langer, A. de Koter, C. J. Evans, I. Hunter, C. Trundle, J.S. Vink submitted to Astronomy & Astrop hysics Ch. 3: ``The VLT-FLAMES Survey of Massive Stars: Rotation and Nitrogen Enrichment as the Key to Understanding Massive Star Evolution'', I.Hunter, I.Brott, D.J. Lennon, N. Langer, C. Trundle, A. de Koter, C.J. Evans and R.S.I. Ryans The Astrophysical Journal, 2008, 676, L29-L32 Ch. 4: ``The VLT-FLAMES Survey of Massive Stars: Constraints on Stellar Evolution from the Chemical Compositions of Rapidly Rotating Galactic and Magellanic Cloud B-type Stars '', I. Hunter, I. Brott, N. Langer, D.J. Lennon, P.L. Dufton, I.D. Howarth R.S.I. Ryan, C. Trundle, C. Evans, A. de Koter and S.J. Smartt Published in Astronomy & Astropysics, 2009, 496, 841- 853 Ch. 5: ``Rotating Massive Main-Sequence Stars II: Simulating a Population of LMC early B-type Stars as a Test of Rotational Mixing '', I. Brott, C. J. Evans, I. Hunter, A. de Koter, N. Langer, P. L. Dufton, M. Cantiello, C. Trundle, D. J. Lennon, S.E. de Mink, S.-C. Yoon, P. Anders submitted to Astronomy & Astrophysics Ch 6: ``The Nature of B Supergiants: Clues From a Steep Drop in Rotation Rates at 22 000 K - The possibility of Bi-stability braking'', Jorick S. Vink, I. Brott, G. Graefener, N. Langer, A. de Koter, D.J. Lennon Astronomy & Astrophysics, 2010, 512, L7

3D NLTE analysis of the most iron-deficient star, SMSS0313-6708

NASA Astrophysics Data System (ADS)

Nordlander, T.; Amarsi, A. M.; Lind, K.; Asplund, M.; Barklem, P. S.; Casey, A. R.; Collet, R.; Leenaarts, J.

2017-01-01

Context. Models of star formation in the early universe require a detailed understanding of accretion, fragmentation and radiative feedback in metal-free molecular clouds. Different simulations predict different initial mass functions of the first stars, ranging from predominantly low-mass (0.1-10 M⊙), to massive (10-100 M⊙), or even supermassive (100-1000 M⊙). The mass distribution of the first stars should lead to unique chemical imprints on the low-mass second and later generation metal-poor stars still in existence. The chemical composition of SMSS0313-6708, which has the lowest abundances of Ca and Fe of any star known, indicates it was enriched by a single massive supernova. Aims: The photospheres of metal-poor stars are relatively transparent in the UV, which may lead to large three-dimensional (3D) effects as well as departures from local thermodynamical equilibrium (LTE), even for weak spectral lines. If 3D effects and departures from LTE (NLTE) are ignored or treated incorrectly, errors in the inferred abundances may significantly bias the inferred properties of the polluting supernovae. We redetermine the chemical composition of SMSS0313-6708by means of the most realistic methods available, and compare the results to predicted supernova yields. Methods: A 3D hydrodynamical Staggermodel atmosphere and 3D NLTE radiative transfer were applied to obtain accurate abundances for Li, Na, Mg, Al, Ca and Fe. The model atoms employ realistic collisional rates, with no calibrated free parameters. Results: We find significantly higher abundances in 3D NLTE than 1D LTE by 0.8 dex for Fe, and 0.5 dex for Mg, Al and Ca, while Li and Na are unaffected to within 0.03 dex. In particular, our upper limit for [Fe/H] is now a factor ten larger, at [Fe/H] < -6.53 (3σ), than previous estimates based on ⟨ 3D ⟩NLTE (I.e., using averaged 3D models). This higher estimate is due to a conservative upper limit estimation, updated NLTE data, and 3D-⟨ 3D ⟩NLTE differences, all of which lead to a higher abundance determination. Conclusions: We find that supernova yields for models in a wide range of progenitor masses reproduce the revised chemical composition. In addition to massive progenitors of 20-60 M⊙ exploding with low energies (1-2 B, where 1 B = 1051 erg), we also find good fits for progenitors of 10 M⊙, with very low explosion energies (<1 B). We cannot reconcile the new abundances with supernovae or hypernovae with explosion energies above 2.5 B, nor with pair-instability supernovae.

Killing-Yano symmetry of Kaluza-Klein black holes in five dimensions

NASA Astrophysics Data System (ADS)

Houri, Tsuyoshi; Yamamoto, Kei

2013-04-01

Using a generalized Killing-Yano equation in the presence of torsion, spacetime metrics admitting a rank-2 generalized Killing-Yano tensor are investigated in five dimensions under the assumption that its eigenvector associated with the zero eigenvalue is a Killing vector field. It is shown that such metrics are classified into three types and the corresponding local expressions are given explicitly. It is also shown that they cover some classes of charged, rotating Kaluza-Klein black hole solutions of minimal supergravity and Abelian heterotic supergravity.

Hidden conformal symmetry of rotating black holes in minimal five-dimensional gauged supergravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Setare, M. R.; Kamali, V.

2010-10-15

In the present paper we show that for a low frequency limit the wave equation of a massless scalar field in the background of nonextremal charged rotating black holes in five-dimensional minimal gauged and ungauged supergravity can be written as the Casimir of an SL(2,R) symmetry. Our result shows that the entropy of the black hole is reproduced by the Cardy formula. Also the absorption cross section is consistent with the finite temperature absorption cross section for a two-dimensional conformal field theory.

The axion mass in modular invariant supergravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Butter, Daniel; Gaillard, Mary K.

2005-02-09

When supersymmetry is broken by condensates with a single condensing gauge group, there is a nonanomalous R-symmetry that prevents the universal axion from acquiring a mass. It has been argued that, in the context of supergravity, higher dimension operators will break this symmetry and may generate an axion mass too large to allow the identification of the universal axion with the QCD axion. We show that such contributions to the axion mass are highly suppressed in a class of models where the effective Lagrangian for gaugino and matter condensation respects modular invariance (T-duality).

On 3D minimal massive gravity

NASA Astrophysics Data System (ADS)

Alishahiha, Mohsen; Qaemmaqami, Mohammad M.; Naseh, Ali; Shirzad, Ahmad

2014-12-01

We study linearized equations of motion of the newly proposed three dimensional gravity, known as minimal massive gravity, using its metric formulation. By making use of a redefinition of the parameters of the model, we observe that the resulting linearized equations are exactly the same as that of TMG. In particular the model admits logarithmic modes at critical points. We also study several vacuum solutions of the model, specially at a certain limit where the contribution of Chern-Simons term vanishes.

Chapter 3. Malpai Borderlands prehistory

Treesearch

Paul R. Fish; Suzanne K. Fish

2006-01-01

Systematic archaeology in the Malpai Borderlands begins with D. D. Gaillard's (1896) map of the elevated Cloverdale Playa beachline in the San Luis Valley. During his involvement with the U.S.-Mexico International Border Survey, Gailard was drawn to this feature by local ranchers' reports of a massive Native American dam. Familiar with the scale of...

Supergravity models with 50-100 TeV scalars, supersymmetry discovery at the LHC, and gravitino decay constraints

NASA Astrophysics Data System (ADS)

Aboubrahim, Amin; Nath, Pran

2017-10-01

We investigate the possibility of testing supergravity unified models with scalar masses in the range 50-100 TeV and much lighter gaugino masses at the Large Hadron Collider. The analysis is carried out under the constraints that models produce the Higgs boson mass consistent with experiment and also produce dark matter consistent with WMAP and PLANCK experiments. A set of benchmarks in the supergravity parameter space are investigated using a combination of signal regions which are optimized for the model set. It is found that some of the models with scalar masses in the 50-100 TeV mass range are discoverable with as little as 100 fb-1 of integrated luminosity and should be accessible at the LHC RUN II. The remaining benchmark models are found to be discoverable with less than 1000 fb-1 of integrated luminosity and thus testable in the high luminosity era of the LHC, i.e., at HL-LHC. It is shown that scalar masses in the 50-100 TeV range but gaugino masses much lower in mass produce unification of gauge coupling constants, consistent with experimental data at low scale, with as good an accuracy (and sometimes even better) as models with low [O (1 ) TeV ] weak scale supersymmetry. Decay of the gravitinos for the supergravity model benchmarks are investigated and it is shown that they decay before the big bang nucleosynthesis (BBN). Further, we investigate the nonthermal production of neutralinos from gravitino decay and it is found that the nonthermal contribution to the dark matter relic density is negligible relative to that from the thermal production of neutralinos for reheat temperature after inflation up to 1 09 GeV . An analysis of the direct detection of dark matter for supergravity grand unified models (SUGRA) with high scalar masses is also discussed. SUGRA models with scalar masses in the range 50-100 TeV have several other attractive features such as they help alleviate the supersymmetric C P problem and help suppress proton decay from baryon and lepton number violating dimension five operators.

Three-dimensional imaging for large LArTPCs

NASA Astrophysics Data System (ADS)

Qian, X.; Zhang, C.; Viren, B.; Diwan, M.

2018-05-01

High-performance event reconstruction is critical for current and future massive liquid argon time projection chambers (LArTPCs) to realize their full scientific potential. LArTPCs with readout using wire planes provide a limited number of 2D projections. In general, without a pixel-type readout it is challenging to achieve unambiguous 3D event reconstruction. As a remedy, we present a novel 3D imaging method, Wire-Cell, which incorporates the charge and sparsity information in addition to the time and geometry through simple and robust mathematics. The resulting 3D image of ionization density provides an excellent starting point for further reconstruction and enables the true power of 3D tracking calorimetry in LArTPCs.

Three-dimensional Imaging for Large LArTPCs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chao, C.; Qian, X.; Viren, B.

2017-12-14

High-performance event reconstruction is critical for current and future massive liquid argon time projection chambers (LArTPCs) to realize their full scientic potential. LArTPCs with readout using wire planes provides a limited number of 2D projections. In general, without a pixel-type readout it is challenging to achieve unambiguous 3D event reconstruction. As a remedy, we present a novel 3D imaging method, Wire-Cell, which incorporates the charge and sparsity information in addition to the time and geometry through simple and robust mathematics.

The hELENa project - I. Stellar populations of early-type galaxies linked with local environment and galaxy mass

NASA Astrophysics Data System (ADS)

Sybilska, A.; Lisker, T.; Kuntschner, H.; Vazdekis, A.; van de Ven, G.; Peletier, R.; Falcón-Barroso, J.; Vijayaraghavan, R.; Janz, J.

2017-09-01

We present the first in a series of papers in The role of Environment in shaping Low-mass Early-type Nearby galaxies (hELENa) project. In this paper, we combine our sample of 20 low-mass early types (dEs) with 258 massive early types (ETGs) from the ATLAS3D survey - all observed with the SAURON integral field unit - to investigate early-type galaxies' stellar population scaling relations and the dependence of the population properties on local environment, extended to the low-σ regime of dEs. The ages in our sample show more scatter at lower σ values, indicative of less massive galaxies being affected by the environment to a higher degree. The shape of the age-σ relations for cluster versus non-cluster galaxies suggests that cluster environment speeds up the placing of galaxies on the red sequence. While the scaling relations are tighter for cluster than for the field/group objects, we find no evidence for a difference in average population characteristics of the two samples. We investigate the properties of our sample in the Virgo cluster as a function of number density (rather than simple clustrocentric distance) and find that dE ages correlate with the local density such that galaxies in regions of lower density are younger, likely because they are later arrivals to the cluster or have experienced less pre-processing in groups, and consequently used up their gas reservoir more recently. Overall, dE properties correlate more strongly with density than those of massive ETGs, which was expected as less massive galaxies are more susceptible to external influences.

The 3D Death of a Massive Star

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2015-07-01

What happens at the very end of a massive star's life, just before its core's collapse? A group led by Sean Couch (California Institute of Technology and Michigan State University) claim to have carried out the first three-dimensional simulations of these final few minutes — revealing new clues about the factors that can lead a massive star to explode in a catastrophic supernova at the end of its life. A Giant Collapses In dying massive stars, in-falling matter bounces off the of collapsed core, creating a shock wave. If the shock wave loses too much energy as it expands into the star, it can stall out — but further energy input can revive it and result in a successful explosion of the star as a core-collapse supernova. In simulations of this process, however, theorists have trouble getting the stars to consistently explode: the shocks often stall out and fail to revive. Couch and his group suggest that one reason might be that these simulations usually start at core collapse assuming spherical symmetry of the progenitor star. Adding Turbulence Couch and his collaborators suspect that the key is in the final minutes just before the star collapses. Models that assume a spherically-symmetric star can't include the effects of convection as the final shell of silicon is burned around the core — and those effects might have a significant impact! To test this hypothesis, the group ran fully 3D simulations of the final three minutes of the life of a 15 solar-mass star, ending with core collapse, bounce, and shock-revival. The outcome was striking: the 3D modeling introduced powerful turbulent convection (with speeds of several hundred km/s!) in the last few minutes of silicon-shell burning. As a result, the initial structure and motions in the star just before core collapse were very different from those in core-collapse simulations that use spherically-symmetric initial conditions. The turbulence was then further amplified during collapse and formation of the shock, generating pressure that aided the shock expansion — which should ultimately help the star explode! The group cautions that their simulations are still very idealized, but these results clearly indicate that the 3D structure of massive stellar cores has an important impact on the core-collapse supernova mechanism. Citation Sean M. Couch et al. 2015 ApJ 808 L21 doi:10.1088/2041-8205/808/1/L21

Wakefield Simulation of CLIC PETS Structure Using Parallel 3D Finite Element Time-Domain Solver T3P

DOE Office of Scientific and Technical Information (OSTI.GOV)

Candel, A.; Kabel, A.; Lee, L.

In recent years, SLAC's Advanced Computations Department (ACD) has developed the parallel 3D Finite Element electromagnetic time-domain code T3P. Higher-order Finite Element methods on conformal unstructured meshes and massively parallel processing allow unprecedented simulation accuracy for wakefield computations and simulations of transient effects in realistic accelerator structures. Applications include simulation of wakefield damping in the Compact Linear Collider (CLIC) power extraction and transfer structure (PETS).

WR 20a Is an Eclipsing Binary: Accurate Determination of Parameters for an Extremely Massive Wolf-Rayet System

NASA Astrophysics Data System (ADS)

Bonanos, A. Z.; Stanek, K. Z.; Udalski, A.; Wyrzykowski, L.; Żebruń, K.; Kubiak, M.; Szymański, M. K.; Szewczyk, O.; Pietrzyński, G.; Soszyński, I.

2004-08-01

We present a high-precision I-band light curve for the Wolf-Rayet binary WR 20a, obtained as a subproject of the Optical Gravitational Lensing Experiment. Rauw et al. have recently presented spectroscopy for this system, strongly suggesting extremely large minimum masses of 70.7+/-4.0 and 68.8+/-3.8 Msolar for the component stars of the system, with the exact values depending strongly on the period of the system. We detect deep eclipses of about 0.4 mag in the light curve of WR 20a, confirming and refining the suspected period of P=3.686 days and deriving an inclination angle of i=74.5d+/-2.0d. Using these photometric data and the radial velocity data of Rauw et al., we derive the masses for the two components of WR 20a to be 83.0+/-5.0 and 82.0+/-5.0 Msolar. Therefore, WR 20a is confirmed to consist of two extremely massive stars and to be the most massive binary known with an accurate mass determination. Based on observations obtained with the 1.3 m Warsaw telescope at Las Campanas Observatory, which is operated by the Carnegie Institute of Washington.

How thermal inflation can save minimal hybrid inflation in supergravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dimopoulos, Konstantinos; Owen, Charlotte

2016-10-12

Minimal hybrid inflation in supergravity has been ruled out by the 2015 Planck observations because the spectral index of the produced curvature perturbation falls outside observational bounds. To resurrect the model, a number of modifications have been put forward but many of them spoil the accidental cancellation that resolves the η-problem and require complicated Kähler constructions to counterbalance the lost cancellation. In contrast, in this paper the model is rendered viable by supplementing the scenario with a brief period of thermal inflation, which follows the reheating of primordial inflation. The scalar field responsible for thermal inflation requires a large non-zeromore » vacuum expectation value (VEV) and a flat potential. We investigate the VEV of such a flaton field and its subsequent effect on the inflationary observables. We find that, for large VEV, minimal hybrid inflation in supergravity produces a spectral index within the 1-σ Planck bound and a tensor-to-scalar ratio which may be observable in the near future. The mechanism is applicable to other inflationary models.« less

Local metrics admitting a principal Killing-Yano tensor with torsion

NASA Astrophysics Data System (ADS)

Houri, Tsuyoshi; Kubizňák, David; Warnick, Claude M.; Yasui, Yukinori

2012-08-01

In this paper we initiate a classification of local metrics admitting the principal Killing-Yano tensor with a skew-symmetric torsion. It is demonstrated that in such spacetimes rank-2 Killing tensors occur naturally and mutually commute. We reduce the classification problem to that of solving a set of partial differential equations, and we present some solutions to these PDEs. In even dimensions, three types of local metrics are obtained: one of them naturally generalizes the torsion-less case while the others occur only when the torsion is present. In odd dimensions, we obtain more varieties of local metrics. The explicit metrics constructed in this paper are not the most general possible admitting the required symmetry; nevertheless, it is demonstrated that they cover a wide variety of solutions of various supergravities, such as the Kerr-Sen black holes of (un-)gauged Abelian heterotic supergravity, the Chong-Cvetic-Lü-Pope black hole solution of five-dimensional minimal supergravity or the Kähler with torsion manifolds. The relation between generalized Killing-Yano tensors and various torsion Killing spinors is also discussed.

Eliminating the η-problem in SUGRA hybrid inflation with vector backreaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dimopoulos, Konstantinos; Wagstaff, Jacques M.; Lazarides, George, E-mail: k.dimopoulos1@lancaster.ac.uk, E-mail: lazaride@eng.auth.gr, E-mail: j.wagstaff@lancaster.ac.uk

2012-02-01

It is shown that, when the inflaton field modulates the gauge kinetic function of the gauge fields in supergravity realisations of inflation, the dynamic backreaction leads to a new inflationary attractor solution, in which the inflaton's variation suffers additional impedance. As a result, slow-roll inflation can naturally occur along directions of the scalar potential which would be too steep and curved to support it otherwise. This provides a generic solution to the infamous eta-problem of inflation in supergravity. Moreover, it is shown that, in the new inflationary attractor, the spectral index of the generated curvature perturbations is kept mildly redmore » despite eta of order unity. The above findings are applied to a model of hybrid inflation in supergravity with a generic Kähler potential. The spectral index of the generated curvature perturbations is found to be 0.97–0.98, in excellent agreement with observations. The gauge field can play the role of the vector curvaton after inflation but observable statistical anisotropy requires substantial tuning of the gauge coupling.« less

How to Remedy the η-problem of SUSY GUT hybrid inflation via vector backreaction

NASA Astrophysics Data System (ADS)

Lazarides, George

2012-07-01

It is shown that, in supergravity models of inflation where the gauge kinetic function of a gauge field is modulated by the inflaton, we can obtain a new inflationary attractor solution, in which the roll-over of the inflaton suffers additional impedance due to the vector field backreaction. As a result, directions of the scalar potential which, due to strong Kähler corrections, become too steep and curved to normally support slow-roll inflation can now naturally do so. This solves the infamous η problem of inflation in supergravity and also keeps the spectral index of the curvature perturbation mildly red despite η of order unity. This mechanism is applied to a model of hybrid inflation in supergravity with a generic Kähler potential. The spectral index of the curvature perturbation is found to be 0.97 - 0.98, in excellent agreement with data. The gauge field can act as vector curvaton generating statistical anisotropy in the curvature perturbation. However, this anisotropy could be possibly observable only if the gauge coupling constant is unnaturally small.

Spontaneous SUSY breaking without R symmetry in supergravity

NASA Astrophysics Data System (ADS)

Maekawa, Nobuhiro; Omura, Yuji; Shigekami, Yoshihiro; Yoshida, Manabu

2018-03-01

We discuss spontaneous supersymmetry (SUSY) breaking in a model with an anomalous U (1 )A symmetry. In this model, the size of the each term in the superpotential is controlled by the U (1 )A charge assignment and SUSY is spontaneously broken via the Fayet-Iliopoulos of U (1 )A at the metastable vacuum. In the global SUSY analysis, the gaugino masses become much smaller than the sfermion masses, because an approximate R symmetry appears at the SUSY breaking vacuum. In this paper, we show that gaugino masses can be as large as gravitino mass, taking the supergravity effect into consideration. This is because the R symmetry is not imposed so that the constant term in the superpotential, which is irrelevant to the global SUSY analysis, largely contributes to the soft SUSY breaking terms in the supergravity. As the mediation mechanism, we introduce the contributions of the field not charged under U (1 )A and the moduli field to cancel the anomaly of U (1 )A. We comment on the application of our SUSY breaking scenario to the grand unified theory.

Weighing the Most Massive Stars

NASA Astrophysics Data System (ADS)

Moffat, Anthony; Schnurr, Olivier; Chené, André-Nicolas; St-Louis, Nicole

2005-08-01

HR diagrams of the brightest stars in nearby galaxies indicate that there exists an upper luminosity limit to star formation. One can assign real masses of stars at that limit, although with low confidence because of uncertainties in current stellar models. Understanding the physics of massive stars is important because these stars dominate the light and ecology of the Universe, not only at the present epoch, but also and especially during the first generation of stars (pop III), expected to be dominated by stars in the range 100-1000 solar masses. The only viable way to determine (or calibrate) masses is by "weighing" them in binary systems. The most massive stars are expected to be formed in the most massive, densest young stellar clusters, like the core R136 of 30 Dor in the Large Magellanic Cloud or its much closer clone NGC 3603 in the Galaxy. Telescopes in space or adaptive-optics systems on large groundbased telescopes are needed to cleanly resolve such stars in order to obtain the necessary high-precision radial velocities and light curves to define the orbits and obtain the masses. We discuss recent progress on this topic, with emphasis on our own attempt to determine the masses of the components of the brightest star (A1, a known main-sequence eclipsing system of type WN6ha + O3: and period 3.7724 d) in the core of NGC 3603, first using HST/STIS (instrument failure) then using VLT/SINFONI (in progress). With A1 being one magnitude intrinsically brighter than the current record holder WR20a (WN6ha + WN6ha, P = 3.686 d, 83 + 82 solar mass), we expect masses for A1 of ~ 100 solar mass if L .M3, or more likely, ~200 solar mass if L . M

Marginal deformations of heterotic G 2 sigma models

NASA Astrophysics Data System (ADS)

Fiset, Marc-Antoine; Quigley, Callum; Svanes, Eirik Eik

2018-02-01

Recently, the infinitesimal moduli space of heterotic G 2 compactifications was described in supergravity and related to the cohomology of a target space differential. In this paper we identify the marginal deformations of the corresponding heterotic nonlinear sigma model with cohomology classes of a worldsheet BRST operator. This BRST operator is nilpotent if and only if the target space geometry satisfies the heterotic supersymmetry conditions. We relate this to the supergravity approach by showing that the corresponding cohomologies are indeed isomorphic. We work at tree-level in α' perturbation theory and study general geometries, in particular with non-vanishing torsion.

CERN Winter School on Supergravity, Strings, and Gauge Theory 2010

ScienceCinema

Sen, Ashoke

2017-12-18

Part 7.The CERN Winter School on Supergravity, Strings, and Gauge Theory is the analytic continuation of the yearly training school of the former EC-RTN string network "Constituents, Fundamental Forces and Symmetries of the Universe". The 2010 edition of the school is supported and organized by the CERN Theory Divison, and will take place from Monday January 25 to Friday January 29, at CERN. As its predecessors, this school is meant primarily for training of doctoral students and young postdoctoral researchers in recent developments in theoretical high-energy physics and string theory. The programme of the school will consist of five series of pedagogical lectures, complemented by tutorial discussion sessions in the afternoons. Previous schools in this series were organized in 2005 at SISSA in Trieste, and in 2006, 2007, 2008, and 2009 at CERN, Geneva. Other similar schools have been organized in the past by the former related RTN network "The Quantum Structure of Spacetime and the Geometric Nature of Fundamental Interactions". This edition of the school is not funded by the European Union. The school is funded by the CERN Theory Division, and the Arnold Sommerfeld Center at Ludwig-Maximilians University of Munich. Scientific committee: M. Gaberdiel, D. Luest, A. Sevrin, J. Simon, K. Stelle, S. Theisen, A. Uranga, A. Van Proeyen, E. Verlinde Local organizers: A. Uranga, J. Walcher

CERN Winter School on Supergravity, Strings, and Gauge Theory 2010

ScienceCinema

None

2018-02-09

The CERN Winter School on Supergravity, Strings, and Gauge Theory is the analytic continuation of the yearly training school of the former EC-RTN string network "Constituents, Fundamental Forces and Symmetries of the Universe". The 2010 edition of the school is supported and organized by the CERN Theory Divison, and will take place from Monday January 25 to Friday January 29, at CERN. As its predecessors, this school is meant primarily for training of doctoral students and young postdoctoral researchers in recent developments in theoretical high-energy physics and string theory. The programme of the school will consist of five series of pedagogical lectures, complemented by tutorial discussion sessions in the afternoons. Previous schools in this series were organized in 2005 at SISSA in Trieste, and in 2006, 2007, 2008, and 2009 at CERN, Geneva. Other similar schools have been organized in the past by the former related RTN network "The Quantum Structure of Spacetime and the Geometric Nature of Fundamental InteractionS". This edition of the school is not funded by the European Union. The school is funded by the CERN Theory Division, and the Arnold Sommerfeld Center at Ludwig-Maximilians University of Munich. Scientific committee: M. Gaberdiel, D. Luest, A. Sevrin, J. Simon, K. Stelle, S. Theisen, A. Uranga, A. Van Proeyen, E. Verlinde Local organizers: A. Uranga, J. Walcher

Conformal twists, Yang–Baxter σ-models & holographic noncommutativity

NASA Astrophysics Data System (ADS)

Araujo, Thiago; Bakhmatov, Ilya; Colgáin, Eoin Ó.; Sakamoto, Jun-ichi; Sheikh-Jabbari, Mohammad M.; Yoshida, Kentaroh

2018-06-01

Expanding upon earlier results (Araujo et al 2017 Phys. Rev. D 95 105006), we present a compendium of σ-models associated with integrable deformations of AdS5 generated by solutions to homogenous classical Yang–Baxter equation. Each example we study from four viewpoints: conformal (Drinfeld) twists, closed string gravity backgrounds, open string parameters and proposed dual noncommutative (NC) gauge theory. Irrespective of whether the deformed background is a solution to supergravity or generalized supergravity, we show that the open string metric associated with each gravity background is undeformed AdS5 with constant open string coupling and the NC structure Θ is directly related to the conformal twist. One novel feature is that Θ exhibits ‘holographic noncommutativity’: while it may exhibit non-trivial dependence on the holographic direction, its value everywhere in the bulk is uniquely determined by its value at the boundary, thus facilitating introduction of a dual NC gauge theory. We show that the divergence of the NC structure Θ is directly related to the unimodularity of the twist. We discuss the implementation of an outer automorphism of the conformal algebra as a coordinate transformation in the AdS bulk and discuss its implications for Yang–Baxter σ-models and self-T-duality based on fermionic T-duality. Finally, we comment on implications of our results for the integrability of associated open strings and planar integrability of dual NC gauge theories.

CERN Winter School on Supergravity, Strings, and Gauge Theory 2010

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2010-01-22

The CERN Winter School on Supergravity, Strings, and Gauge Theory is the analytic continuation of the yearly training school of the former EC-RTN string network "Constituents, Fundamental Forces and Symmetries of the Universe". The 2010 edition of the school is supported and organized by the CERN Theory Divison, and will take place from Monday January 25 to Friday January 29, at CERN. As its predecessors, this school is meant primarily for training of doctoral students and young postdoctoral researchers in recent developments in theoretical high-energy physics and string theory. The programme of the school will consist of five series ofmore » pedagogical lectures, complemented by tutorial discussion sessions in the afternoons. Previous schools in this series were organized in 2005 at SISSA in Trieste, and in 2006, 2007, 2008, and 2009 at CERN, Geneva. Other similar schools have been organized in the past by the former related RTN network "The Quantum Structure of Spacetime and the Geometric Nature of Fundamental Interactions". This edition of the school is not funded by the European Union. The school is funded by the CERN Theory Division, and the Arnold Sommerfeld Center at Ludwig-Maximilians University of Munich. Scientific committee: M. Gaberdiel, D. Luest, A. Sevrin, J. Simon, K. Stelle, S. Theisen, A. Uranga, A. Van Proeyen, E. Verlinde Local organizers: A. Uranga, J. Walcher« less

Ambitwistor formulations of R 2 gravity and ( DF)2 gauge theories

NASA Astrophysics Data System (ADS)

Azevedo, Thales; Engelund, Oluf Tang

2017-11-01

We consider D-dimensional amplitudes in R 2 gravities (conformal gravity in D = 4) and in the recently introduced ( DF)2 gauge theory, from the perspective of the CHY formulae and ambitwistor string theory. These theories are related through the BCJ double-copy construction, and the ( DF)2 gauge theory obeys color-kinematics duality. We work out the worldsheet details of these theories and show that they admit a formulation as integrals on the support of the scattering equations, or alternatively, as ambitwistor string theories. For gravity, this generalizes the work done by Berkovits and Witten on conformal gravity to D dimensions. The ambitwistor is also interpreted as a D-dimensional generalization of Witten's twistor string (SYM + conformal supergravity). As part of our ambitwistor investigation, we discover another ( DF)2 gauge theory containing a photon that couples to Einstein gravity. This theory can provide an alternative KLT description of Einstein gravity compared to the usual Yang-Mills squared.

High fibrin/fibrinogen degradation product to fibrinogen ratio is associated with 28-day mortality and massive transfusion in severe trauma.

PubMed

Lee, D H; Lee, B K; Noh, S M; Cho, Y S

2018-04-01

There is a lack of association between coagulation biomarkers and long-term mortality in severe trauma. We aimed to investigate the association between coagulation biomarkers on admission and outcome of late stage of trauma. This retrospective observational study included patients admitted with severe trauma between 2012 and 2015. We used the area under the receiver operating characteristic curve (AUROC) of coagulation biomarkers to determine 28-day mortality. Head Abbreviated Injury Scale scores greater than 3 were defined as traumatic brain injury (TBI). The primary outcome was 28-day mortality and the secondary outcome was massive transfusion. Of the 1266 patients included in the study, 28-day mortality rate was 19.7% (n = 249) and 7.9% (n = 100) of patients received massive transfusion. The AUROC of fibrin/fibrinogen degradation product (FDP) to fibrinogen ratio had a significantly higher prognostic performance than other markers. Multivariate analysis revealed that D-dimer level [odds ratio (OR) 1.033; 95% confidence interval (CI) 1.016-1.051] and FDP/fibrinogen ratio (OR 1.007; 95% CI 1.001-1.013) were independently associated with 28-day mortality. D-dimer (OR 1.028; 95% CI 1.003-1.055) and FDP/fibrinogen ratio (OR 1.035; 95% CI 1.012-1.058) were associated with 28-day mortality in the TBI group. In the non-TBI group, D-dimer was associated with 28-day mortality (OR 1.033; 95% CI 1.008-1.059), but the FDP/fibrinogen ratio was not. FDP/fibrinogen ratio, not D-dimer level, was an independent predictor for massive transfusion (OR 1.005; 95% CI 1.001-1.010). High FDP/fibrinogen ratio on arrival is a predictor of 28-day mortality and the requirement for massive transfusion in severe trauma.

Exact Holography of Massive M2-brane Theories and Entanglement Entropy

NASA Astrophysics Data System (ADS)

Jang, Dongmin; Kim, Yoonbai; Kwon, O.-Kab; Tolla, D. D.

2018-01-01

We test the gauge/gravity duality between the N = 6 mass-deformed ABJM theory with Uk(N) × U-k(N) gauge symmetry and the 11-dimensional supergravity on LLM geometries with SO(4)=ℤk × SO(4)=ℤk isometry. Our analysis is based on the evaluation of vacuum expectation values of chiral primary operators from the supersymmetric vacua of mass-deformed ABJM theory and from the implementation of Kaluza-Klein (KK) holography to the LLM geometries. We focus on the chiral primary operator (CPO) with conformal dimension Δ = 1. The non-vanishing vacuum expectation value (vev) implies the breaking of conformal symmetry. In that case, we show that the variation of the holographic entanglement entropy (HEE) from it's value in the CFT, is related to the non-vanishing one-point function due to the relevant deformation as well as the source field. Applying Ryu Takayanagi's HEE conjecture to the 4-dimensional gravity solutions, which are obtained from the KK reduction of the 11-dimensional LLM solutions, we calculate the variation of the HEE. We show how the vev and the value of the source field determine the HEE.

Three-dimensional imaging for large LArTPCs

DOE PAGES

Qian, X.; Zhang, Chao; Viren, B.; ...

2018-05-29

High-performance event reconstruction is critical for current and future massive liquid argon time projection chambers (LArTPCs) to realize their full scientific potential. LArTPCs with readout using wire planes provide a limited number of 2D projections. In general, without a pixel- type readout it is challenging to achieve unambiguous 3D event reconstruction. As a remedy, we present a novel 3D imaging method, Wire-Cell, which incorporates the charge and sparsity information in addition to the time and geometry through simple and robust mathematics. Furthermore, the resulting 3D image of ionization density provides an excellent starting point for further reconstruction and enables themore » true power of 3D tracking calorimetry in LArTPCs.« less

Three-dimensional imaging for large LArTPCs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qian, X.; Zhang, Chao; Viren, B.

High-performance event reconstruction is critical for current and future massive liquid argon time projection chambers (LArTPCs) to realize their full scientific potential. LArTPCs with readout using wire planes provide a limited number of 2D projections. In general, without a pixel- type readout it is challenging to achieve unambiguous 3D event reconstruction. As a remedy, we present a novel 3D imaging method, Wire-Cell, which incorporates the charge and sparsity information in addition to the time and geometry through simple and robust mathematics. Furthermore, the resulting 3D image of ionization density provides an excellent starting point for further reconstruction and enables themore » true power of 3D tracking calorimetry in LArTPCs.« less

N=2 supersymmetry in two-dimensional dilaton gravity

NASA Astrophysics Data System (ADS)

Nelson, William M.; Park, Youngchul

1993-11-01

Actions for D=2, N=2 supergravity coupled to a scalar field are calculated, and it is shown that the most general power-counting renormalizable dilaton gravity action has an N=2 locally supersymmetric extension. The presence of chiral terms in the action leads one to hope that nonrenormalization theorems similar to those in global SUSY will apply; this would eliminate some of the renormalization ambiguities which plague ordinary bosonic (and N=1) dilaton gravity. To investigate this, the model is studied in the superconformal gauge, where it is found that one chiral term becomes nonchiral, so that only one term is safe from renormalization.

A fully coupled method for massively parallel simulation of hydraulically driven fractures in 3-dimensions: FULLY COUPLED PARALLEL SIMULATION OF HYDRAULIC FRACTURES IN 3-D

DOE PAGES

Settgast, Randolph R.; Fu, Pengcheng; Walsh, Stuart D. C.; ...

2016-09-18

This study describes a fully coupled finite element/finite volume approach for simulating field-scale hydraulically driven fractures in three dimensions, using massively parallel computing platforms. The proposed method is capable of capturing realistic representations of local heterogeneities, layering and natural fracture networks in a reservoir. A detailed description of the numerical implementation is provided, along with numerical studies comparing the model with both analytical solutions and experimental results. The results demonstrate the effectiveness of the proposed method for modeling large-scale problems involving hydraulically driven fractures in three dimensions.

A fully coupled method for massively parallel simulation of hydraulically driven fractures in 3-dimensions: FULLY COUPLED PARALLEL SIMULATION OF HYDRAULIC FRACTURES IN 3-D

DOE Office of Scientific and Technical Information (OSTI.GOV)

Settgast, Randolph R.; Fu, Pengcheng; Walsh, Stuart D. C.

This study describes a fully coupled finite element/finite volume approach for simulating field-scale hydraulically driven fractures in three dimensions, using massively parallel computing platforms. The proposed method is capable of capturing realistic representations of local heterogeneities, layering and natural fracture networks in a reservoir. A detailed description of the numerical implementation is provided, along with numerical studies comparing the model with both analytical solutions and experimental results. The results demonstrate the effectiveness of the proposed method for modeling large-scale problems involving hydraulically driven fractures in three dimensions.

Experiments in DIII-D Toward Achieving Rapid Shutdown with Runaway Electron Suppression

NASA Astrophysics Data System (ADS)

Hollmann, E. M.

2009-11-01

For safe discharge shutdown in future large tokamaks in the event of an unavoidable disruption, it is important to develop rapid (˜ several ms)shutdown methods to avoid large runaway electron currents, which pose a serious threat to plasma facing components. Prevention of runaway current formation has been proposed by either increasing electron-electron collisionality with massive particle injection, or magnetically by using externally applied non-axisymmetric fields to increase radial diffusive losses of a runaway seed population. Experiments studying both approaches have been pursued in the DIII-D tokamak. For collisional suppression, three different rapid shutdown methods are being investigated: massive gas injection, massive shattered cryogenic pellet injection, and polystyrene shell pellet injection. First-of-kind demonstrations of fast shutdowns were produced by 3000 Torr-l (0.8-g) shattered D2 pellets and large, 10-mm diameter, 0.3-g polystyrene shell pellets filled with boron powder. The application of external magnetic perturbations shows promising preliminary results in suppressing seed runaway electrons, although lack of repeatability in the runaway seed term made these results challenging to interpret. Experiments have been performed to help understand how runaways form and are transported during rapid shutdown. These experiments confirm that the commonly used 0D loop voltage + Dreicer evaporation picture of runaway seed formation is not applicable here, with relativistic E > 0.5,MeV electrons forming before any external loop voltage appears. Present applications of 0D, 1D, and 2D models to the rapid shutdown and runaway confinement experiments, as well as preliminary extrapolations to ITER, will be discussed.

Radiation-driven Turbulent Accretion onto Massive Black Holes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, KwangHo; Wise, John H.; Bogdanović, Tamara, E-mail: kwangho.park@physics.gatech.edu

Accretion of gas and interaction of matter and radiation are at the heart of many questions pertaining to black hole (BH) growth and coevolution of massive BHs and their host galaxies. To answer them, it is critical to quantify how the ionizing radiation that emanates from the innermost regions of the BH accretion flow couples to the surrounding medium and how it regulates the BH fueling. In this work, we use high-resolution three-dimensional (3D) radiation-hydrodynamic simulations with the code Enzo , equipped with adaptive ray-tracing module Moray , to investigate radiation-regulated BH accretion of cold gas. Our simulations reproduce findingsmore » from an earlier generation of 1D/2D simulations: the accretion-powered UV and X-ray radiation forms a highly ionized bubble, which leads to suppression of BH accretion rate characterized by quasi-periodic outbursts. A new feature revealed by the 3D simulations is the highly turbulent nature of the gas flow in vicinity of the ionization front. During quiescent periods between accretion outbursts, the ionized bubble shrinks in size and the gas density that precedes the ionization front increases. Consequently, the 3D simulations show oscillations in the accretion rate of only ∼2–3 orders of magnitude, significantly smaller than 1D/2D models. We calculate the energy budget of the gas flow and find that turbulence is the main contributor to the kinetic energy of the gas but corresponds to less than 10% of its thermal energy and thus does not contribute significantly to the pressure support of the gas.« less

Type IIB flux vacua from G-theory II

NASA Astrophysics Data System (ADS)

Candelas, Philip; Constantin, Andrei; Damian, Cesar; Larfors, Magdalena; Morales, Jose Francisco

2015-02-01

We find analytic solutions of type IIB supergravity on geometries that locally take the form Mink × M 4 × ℂ with M 4 a generalised complex manifold. The solutions involve the metric, the dilaton, NSNS and RR flux potentials (oriented along the M 4) parametrised by functions varying only over ℂ. Under this assumption, the supersymmetry equations are solved using the formalism of pure spinors in terms of a finite number of holomorphic functions. Alternatively, the solutions can be viewed as vacua of maximally supersymmetric supergravity in six dimensions with a set of scalar fields varying holomorphically over ℂ. For a class of solutions characterised by up to five holomorphic functions, we outline how the local solutions can be completed to four-dimensional flux vacua of type IIB theory. A detailed study of this global completion for solutions with two holomorphic functions has been carried out in the companion paper [1]. The fluxes of the global solutions are, as in F-theory, entirely codified in the geometry of an auxiliary K3 fibration over ℂℙ1. The results provide a geometric construction of fluxes in F-theory.

The large N limit of superconformal field theories and supergravity

NASA Astrophysics Data System (ADS)

Maldacena, Juan

1999-07-01

We show that the large N limit of certain conformal field theories in various dimensions include in their Hilbert space a sector describing supergravity on the product of Anti-deSitter spacetimes, spheres and other compact manifolds. This is shown by taking some branes in the full M/string theory and then taking a low energy limit where the field theory on the brane decouples from the bulk. We observe that, in this limit, we can still trust the near horizon geometry for large N. The enhanced supersymmetries of the near horizon geometry correspond to the extra supersymmetry generators present in the superconformal group (as opposed to just the super-Poincare group). The 't Hooft limit of 3+1N=4 super-Yang-Mills at the conformal point is shown to contain strings: they are IIB strings. We conjecture that compactifications of M/string theory on various Anti-deSitter spacetimes is dual to various conformal field theories. This leads to a new proposal for a definition of M-theory which could be extended to include five non-compact dimensions.

$$ \\mathcal{N} $$ = 2 supersymmetric Janus solutions and flows: From gauged supergravity to M theory

DOE PAGES

Pilch, Krzysztof; Tyukov, Alexander; Warner, Nicholas P.

2016-05-02

In this study, we investigate a family of SU(3)×U(1)×U(1)-invariant holographic flows and Janus solutions obtained from gaugedmore » $$ \\mathcal{N} $$ = 8 supergravity in four dimensions. We give complete details of how to use the uplift formulae to obtain the corresponding solutions in M theory. While the flow solutions appear to be singular from the four-dimensional perspective, we find that the eleven-dimensional solutions are much better behaved and give rise to interesting new classes of compactification geometries that are smooth, up to orbifolds, in the infra-red limit. Our solutions involve new phases in which M2 branes polarize partially or even completely into M5 branes. We derive the eleven-dimensional supersymmetries and show that the eleven-dimensional equations of motion and BPS equations are indeed satisfied as a consequence of their four-dimensional counterparts. Apart from elucidating a whole new class of eleven-dimensional Janus and flow solutions, our work provides extensive and highly non-trivial tests of the recently-derived uplift formulae.« less

The wasteland of random supergravities

NASA Astrophysics Data System (ADS)

Marsh, David; McAllister, Liam; Wrase, Timm

2012-03-01

We show that in a general {N} = {1} supergravity with N ≫ 1 scalar fields, an exponentially small fraction of the de Sitter critical points are metastable vacua. Taking the superpotential and Kähler potential to be random functions, we construct a random matrix model for the Hessian matrix, which is well-approximated by the sum of a Wigner matrix and two Wishart matrices. We compute the eigenvalue spectrum analytically from the free convolution of the constituent spectra and find that in typical configurations, a significant fraction of the eigenvalues are negative. Building on the Tracy-Widom law governing fluctuations of extreme eigenvalues, we determine the probability P of a large fluctuation in which all the eigenvalues become positive. Strong eigenvalue repulsion makes this extremely unlikely: we find P ∝ exp(- c N p ), with c, p being constants. For generic critical points we find p ≈ 1 .5, while for approximately-supersymmetric critical points, p ≈ 1 .3. Our results have significant implications for the counting of de Sitter vacua in string theory, but the number of vacua remains vast.

Dual actions for massless, partially-massless and massive gravitons in (A)dS

NASA Astrophysics Data System (ADS)

Boulanger, N.; Campoleoni, A.; Cortese, I.

2018-07-01

We provide a unified treatment of electric-magnetic duality, at the action level and with manifest Lorentz invariance, for massive, massless as well as partially-massless gravitons propagating in maximally symmetric spacetimes of any dimension n > 3. For massive and massless fields, we complete previous analyses that use parent-action techniques by giving dual descriptions that enable direct counting of physical degrees of freedom in the flat and massless limit. The same treatment is extended to the partially-massless case, where the duality has been previously discussed in covariant form only at the level of the equations of motion. The nature of the dual graviton is therefore clarified for all values of the mass and of the cosmological constant.

Openwebglobe 2: Visualization of Complex 3D-GEODATA in the (mobile) Webbrowser

NASA Astrophysics Data System (ADS)

Christen, M.

2016-06-01

Providing worldwide high resolution data for virtual globes consists of compute and storage intense tasks for processing data. Furthermore, rendering complex 3D-Geodata, such as 3D-City models with an extremely high polygon count and a vast amount of textures at interactive framerates is still a very challenging task, especially on mobile devices. This paper presents an approach for processing, caching and serving massive geospatial data in a cloud-based environment for large scale, out-of-core, highly scalable 3D scene rendering on a web based virtual globe. Cloud computing is used for processing large amounts of geospatial data and also for providing 2D and 3D map data to a large amount of (mobile) web clients. In this paper the approach for processing, rendering and caching very large datasets in the currently developed virtual globe "OpenWebGlobe 2" is shown, which displays 3D-Geodata on nearly every device.

Ultraviolet divergences in non-renormalizable supersymmetric theories

NASA Astrophysics Data System (ADS)

Smilga, A.

2017-03-01

We present a pedagogical review of our current understanding of the ultraviolet structure of N = (1,1) 6D supersymmetric Yang-Mills theory and of N = 8 4 D supergravity. These theories are not renormalizable, they involve power ultraviolet divergences and, in all probability, an infinite set of higherdimensional counterterms that contribute to on-mass-shell scattering amplitudes. A specific feature of supersymmetric theories (especially, of extended supersymmetric theories) is that these counterterms may not be invariant off shell under the full set of supersymmetry transformations. The lowest-dimensional nontrivial counterterm is supersymmetric on shell. Still higher counterterms may lose even the on-shell invariance. On the other hand, the full effective Lagrangian, generating the amplitudes and representing an infinite sum of counterterms, still enjoys the complete symmetry of original theory. We also discuss simple supersymmetric quantum-mechanical models that exhibit the same behaviour.

Physics from geometry: Non-Kahler compactifications, black rings anddS/CFT

NASA Astrophysics Data System (ADS)

Cyrier, Michelle

The spectrum that arises in four dimensions from compactification of ten dimensional string theory onto six dimensional manifolds is determined entirely by the geometry of the compactification manifold. The massless spectrum for compactifications on Calabi-Yau threefolds, which are Kahler and have complex structure, is well understood. In chapter 2 of this thesis, We study the compactification of heterotic string theory on manifolds that are non-Kahler. Such manifolds arise as a solution for compactifications of heterotic string theory with nonzero H-flux. We begin the study of the massless spectrum arising from compactification using this construction by counting zero modes of the linearized equations of motion for the gaugino in the supergravity approximation. We rephrase the question in terms of a cohomology problem and show that for a trivial gauge bundle, this cohomology reduces to the Dolbeault cohomology of the 3-fold, which we then compute. Another check of string theory is to study the entropy of black holes made in string theory. In Chapter 3, We review the microstate counting of four dimensional black holes made from M theory. We then describe a new solution in five dimensions, the supersymmetric black ring, and describe its microscopic entropy using a similar counting. These agree with the semi-classical Bekenstein-Hawking entropy for these black holes. Finally, one powerful tool for quantum gravity is the holographic duality of string theory in an Anti de Sitter background and a theory living on its conformal boundary. Strominger conjectured a similar duality between quantum gravity in a de Sitter background and the corresponding theory on its boundary. In chapter 4 we examine issues with different representations of the conformal field theory on the boundary for a massive quantum field theory living in the bulk and try to write down a sensible CFT.

The Green-Schwarz mechanism and geometric anomaly relations in 2d (0,2) F-theory vacua

NASA Astrophysics Data System (ADS)

Weigand, Timo; Xu, Fengjun

2018-04-01

We study the structure of gauge and gravitational anomalies in 2d N = (0 , 2) theories obtained by compactification of F-theory on elliptically fibered Calabi-Yau 5-folds. Abelian gauge anomalies, induced at 1-loop in perturbation theory, are cancelled by a generalized Green-Schwarz mechanism operating at the level of chiral scalar fields in the 2d supergravity theory. We derive closed expressions for the gravitational and the non-abelian and abelian gauge anomalies including the Green-Schwarz counterterms. These expressions involve topological invariants of the underlying elliptic fibration and the gauge background thereon. Cancellation of anomalies in the effective theory predicts intricate topological identities which must hold on every elliptically fibered Calabi-Yau 5-fold. We verify these relations in a non-trivial example, but their proof from a purely mathematical perspective remains as an interesting open problem. Some of the identities we find on elliptic 5-folds are related in an intriguing way to previously studied topological identities governing the structure of anomalies in 6d N = (1 , 0) and 4d N = 1 theories obtained from F-theory.

Precision holography for N={2}^{\\ast } on S 4 from type IIB supergravity

NASA Astrophysics Data System (ADS)

Bobev, Nikolay; Gautason, Friðrik Freyr; van Muiden, Jesse

2018-04-01

We find a new supersymmetric solution of type IIB supergravity which is holographically dual to the planar limit of the four-dimensional N={2}^{\\ast } supersymmetric Yang-Mills theory on S 4. We study a probe fundamental string in this background which is dual to a supersymmetric Wilson loop in the N={2}^{\\ast } theory. Using holography we calculate the expectation value of this line operator to leading order in the 't Hooft coupling. The result is a non-trivial function of the mass parameter of the N={2}^{\\ast } theory that precisely matches the result from supersymmetric localization.

Supergravity inflation free from harmful relics

NASA Astrophysics Data System (ADS)

Greene, Patrick B.; Kadota, Kenji; Murayama, Hitoshi

2003-08-01

We present a realistic supergravity inflation model that is free from the overproduction of potentially dangerous relics in cosmology, namely, moduli and gravitinos, which can lead to inconsistencies with the predictions of baryon asymmetry and nucleosynthesis. The radiative correction turns out to play a crucial role in our analysis, raising the mass of the supersymmetry breaking field to an intermediate scale. We pay particular attention to the nonthermal production of gravitinos using the nonminimal Kähler potential we obtained from loop correction. This nonthermal gravitino production is diminished, however, because of the relatively small scale of the inflaton mass and the small amplitudes of the hidden sector fields.

Warped AdS 6 × S 2 in Type IIB supergravity III. Global solutions with seven-branes

NASA Astrophysics Data System (ADS)

D'Hoker, Eric; Gutperle, Michael; Uhlemann, Christoph F.

2017-11-01

We extend our previous construction of global solutions to Type IIB super-gravity that are invariant under the superalgebra F(4) and are realized on a spacetime of the form AdS 6 × S 2 warped over a Riemann surface Σ by allowing the supergravity fields to have non-trivial SL(2, ℝ) monodromy at isolated punctures on Σ. We obtain explicit solutions for the case where Σ is a disc, and the monodromy generators are parabolic elements of SL(2, ℝ) physically corresponding to the monodromy allowed in Type IIB string theory. On the boundary of Σ the solutions exhibit singularities at isolated points which correspond to semi-infinite five-branes, as is familiar from the global solutions without monodromy. In the interior of Σ, the solutions are everywhere regular, except at the punctures where SL(2, ℝ) monodromy resides and which physically correspond to the locations of [ p, q] seven-branes. The solutions have a compelling physical interpretation corresponding to fully localized five-brane intersections with additional seven-branes, and provide candidate holographic duals to the five-dimensional superconformal field theories realized on such intersections.

Weyl and transverse diffeomorphism invariant spin-2 models in D=2+1

NASA Astrophysics Data System (ADS)

Dalmazi, Denis; dos Santos, A. L. R.; Ghosh, Subir; Mendonça, E. L.

2017-09-01

There are two covariant descriptions of massless spin-2 particles in D=3+1 via a symmetric rank-2 tensor: the linearized Einstein-Hilbert (LEH) theory and the Weyl plus transverse diffeomorphism (WTDIFF) invariant model. From the LEH theory one can obtain the linearized new massive gravity (NMG) in D=2+1 via Kaluza-Klein dimensional reduction followed by a dual master action. Here we show that a similar route takes us from the WTDIFF model to a linearized scalar-tensor NMG which belongs to a larger class of consistent spin-0 modifications of NMG. We also show that a traceless master action applied to a parity singlet furnishes two new spin-2 self-dual models. Moreover, we examine the singular replacement h_{μ ν } → h_{μ ν } - η _{μ ν }h/D and prove that it leads to consistent massive spin-2 models in D=2+1. They include linearized versions of unimodular topologically massive gravity (TMG) and unimodular NMG. Although the free part of those unimodular theories are Weyl invariant, we do not expect any improvement in the renormalizability. Both the linearized K-term (in NMG) and the linearized gravitational Chern-Simons term (in TMG) are invariant under longitudinal reparametrizations δ h_{μ ν } = partial _{μ }partial _{ν }ζ , which is not a symmetry of the WTDIFF Einstein-Hilbert term. Therefore, we still have one degree of freedom whose propagator behaves like 1/p^2 for large momentum.

SPIM-fluid: open source light-sheet based platform for high-throughput imaging

PubMed Central

Gualda, Emilio J.; Pereira, Hugo; Vale, Tiago; Estrada, Marta Falcão; Brito, Catarina; Moreno, Nuno

2015-01-01

Light sheet fluorescence microscopy has recently emerged as the technique of choice for obtaining high quality 3D images of whole organisms/embryos with low photodamage and fast acquisition rates. Here we present an open source unified implementation based on Arduino and Micromanager, which is capable of operating Light Sheet Microscopes for automatized 3D high-throughput imaging on three-dimensional cell cultures and model organisms like zebrafish, oriented to massive drug screening. PMID:26601007

Quasar-mode Feedback in Nearby Type 1 Quasars: Ubiquitous Kiloparsec-scale Outflows and Correlations with Black Hole Properties

NASA Astrophysics Data System (ADS)

Rupke, David S. N.; Gültekin, Kayhan; Veilleux, Sylvain

2017-11-01

The prevalence and properties of kiloparsec-scale outflows in nearby Type 1 quasars have been the subject of little previous attention. This work presents Gemini integral field spectroscopy of 10 Type 1 radio-quiet quasars at z< 0.3. The excellent image quality, coupled with a new technique to remove the point-spread function using spectral information, allows the fitting of the underlying host on a spaxel-by-spaxel basis. Fits to stars, line-emitting gas, and interstellar absorption show that 100% of the sample hosts warm ionized and/or cool neutral outflows with spatially averaged velocities (< {v}98 % > \\equiv < v+2σ > ) of 200-1300 {km} {{{s}}}-1 and peak velocities (maximum {v}98 % ) of 500-2600 {km} {{{s}}}-1. These minor-axis outflows are powered primarily by the central active galactic nucleus, reach scales of 3-12 kpc, and often fill the field of view. Including molecular data and Type 2 quasar measurements, nearby quasars show a wide range in mass outflow rates ({dM}/{dt}=1 to > 1000 {M}⊙ {{yr}}-1) and momentum boosts [(c {dp}/{dt})/{L}{AGN}=0.01{--}20]. After extending the mass scale to Seyferts, dM/dt and dE/dt correlate with black hole mass ({dM}/{dt}˜ {M}{BH}0.7+/- 0.3 and {dE}/{dt}˜ {M}{BH}1.3+/- 0.5). Thus, the most massive black holes in the local universe power the most massive and energetic quasar-mode winds.

White matter segmentation by estimating tissue optical attenuation from volumetric OCT massive histology of whole rodent brains

NASA Astrophysics Data System (ADS)

Lefebvre, Joël.; Castonguay, Alexandre; Lesage, Frédéric

2017-02-01

A whole rodent brain was imaged using an automated massive histology setup and an Optical Coherence Tomography (OCT) microscope. Thousands of OCT volumetric tiles were acquired, each covering a size of about 2.5x2.5x0.8 mm3 with a sampling resolution of 4.9x4.9x6.5 microns. This paper shows the techniques for reconstruction, attenuation compensation and segmentation of the sliced brains. The tile positions within the mosaic were evaluated using a displacement model of the motorized stage and pairwise coregistration. Volume blending was then performed by solving the 3D Laplace equation, and consecutive slices were assembled using the cross-correlation of their 2D image gradient. This reconstruction algorithm resulted in a 3D map of optical reflectivity for the whole brain at micrometric resolution. OCT tissue slices were then used to estimate the local attenuation coefficient based on a single scattering photon model. The attenuation map obtained exhibits a high contrast for all white matter fibres, regardless of their orientation. The tissue optical attenuation from the intrinsic OCT reflectivity contributes to better white matter tissue segmentation. The combined 3D maps of reflectivity and attenuation is a step toward the study of white matter at a microscopic scale for the whole brain in small animals.

Massive parallel 3D PIC simulation of negative ion extraction

NASA Astrophysics Data System (ADS)

Revel, Adrien; Mochalskyy, Serhiy; Montellano, Ivar Mauricio; Wünderlich, Dirk; Fantz, Ursel; Minea, Tiberiu

2017-09-01

The 3D PIC-MCC code ONIX is dedicated to modeling Negative hydrogen/deuterium Ion (NI) extraction and co-extraction of electrons from radio-frequency driven, low pressure plasma sources. It provides valuable insight on the complex phenomena involved in the extraction process. In previous calculations, a mesh size larger than the Debye length was used, implying numerical electron heating. Important steps have been achieved in terms of computation performance and parallelization efficiency allowing successful massive parallel calculations (4096 cores), imperative to resolve the Debye length. In addition, the numerical algorithms have been improved in terms of grid treatment, i.e., the electric field near the complex geometry boundaries (plasma grid) is calculated more accurately. The revised model preserves the full 3D treatment, but can take advantage of a highly refined mesh. ONIX was used to investigate the role of the mesh size, the re-injection scheme for lost particles (extracted or wall absorbed), and the electron thermalization process on the calculated extracted current and plasma characteristics. It is demonstrated that all numerical schemes give the same NI current distribution for extracted ions. Concerning the electrons, the pair-injection technique is found well-adapted to simulate the sheath in front of the plasma grid.

Preliminary interpretation of high resolution 3D seismic data from offshore Mt. Etna, Italy

NASA Astrophysics Data System (ADS)

Gross, F.; Krastel, S.; Chiocci, F. L.; Ridente, D.; Cukur, D.; Bialas, J.; Papenberg, C. A.; Crutchley, G.; Koch, S.

2013-12-01

In order to gain knowledge about subsurface structures and its correlation to seafloor expressions, a hydro-acoustic dataset was collected during RV Meteor Cruise M86/2 (December 2011/January 2012) in Messina Straits and offshore Mt. Etna. Especially offshore Mt. Etna, the data reveals an obvious connection between subsurface structures and previously known morphological features at the sea floor. Therefore a high resolution 3D seismic dataset was acquired between Riposto Ridge and Catania Canyon close to the shore of eastern Sicily. The study area is characterized by a major structural high, which hosts several ridge-like features at the seafloor. These features are connected to a SW-NE trending fault system. The ridges are bended in their NE-SW direction and host major escarpments at the seafloor. Furthermore they are located directly next to a massive amphitheater structure offshore Mt. Etna with slope gradients of up to 35°, which is interpreted as remnants of a massive submarine mass wasting event off Sicily. The new 3D seismic dataset allows an in depth analysis of the ongoing deformation of the east flank of Mt. Etna.

The value of automated gel column agglutination technology in the identification of true inherited D blood types in massively transfused patients.

PubMed

Summers, Thomas; Johnson, Viviana V; Stephan, John P; Johnson, Gloria J; Leonard, George

2009-08-01

Massive transfusion of D- trauma patients in the combat setting involves the use of D+ red blood cells (RBCs) or whole blood along with suboptimal pretransfusion test result documentation. This presents challenges to the transfusion service of tertiary care military hospitals who ultimately receive these casualties because initial D typing results may only reflect the transfused RBCs. After patients are stabilized, mixed-field reaction results on D typing indicate the patient's true inherited D phenotype. This case series illustrates the utility of automated gel column agglutination in detecting mixed-field reactions in these patients. The transfusion service test results, including the automated gel column agglutination D typing results, of four massively transfused D- patients transfused D+ RBCs is presented. To test the sensitivity of the automated gel column agglutination method in detecting mixed-field agglutination reactions, a comparative analysis of three automated technologies using predetermined mixtures of D+ and D- RBCs is also presented. The automated gel column agglutination method detected mixed-field agglutination in D typing in all four patients and in the three prepared control specimens. The automated microwell tube method identified one of the three prepared control specimens as indeterminate, which was subsequently manually confirmed as a mixed-field reaction. The automated solid-phase method was unable to detect any mixed fields. The automated gel column agglutination method provides a sensitive means for detecting mixed-field agglutination reactions in the determination of the true inherited D phenotype of combat casualties transfused massive amounts of D+ RBCs.

Branched Polymers for Enhancing Polymer Gel Strength and Toughness

DTIC Science & Technology

2013-02-01

Molecular Massively Parallel Simulator ( LAMMPS ) program and the stress-strain relations were calculated with varying strain-rates (figure 6). A...Acronyms ARL U.S. Army Research Laboratory D3 hexamethylcyclotrisiloxane FTIR Fourier transform infrared GPC gel permeation chromatography LAMMPS

Dynamical History Of The Local Group In ΛCDM slowromancapii@ - Including External Perturbers In 3D

NASA Astrophysics Data System (ADS)

Banik, Indranil; Zhao, Hongsheng

2017-05-01

We attempt to fit the observed radial velocities (RVs) of ˜30 Local Group (LG) galaxies using a 3D dynamical model of it and its immediate environment within the context of the standard cosmological paradigm, Λ cold dark matter (CDM). This extends and confirms the basic results of our previous axisymmetric investigation of the LG. We find that there remains a tendency for observed RVs to exceed those predicted by our best-fitting model. The typical mismatch is slightly higher than in our 2D model, with a root mean square value of ˜50 km s-1. Our main finding is that including the 3D distribution of massive perturbing dark matter haloes is unlikely to help greatly with the high-velocity galaxy problem. None the less, the 2D and 3D results differ in several other ways such as which galaxies' RVs are most problematic and the preferred values of parameters common to both models. The anomalously high RVs of several LG dwarfs may be better explained if the Milky Way (MW) and Andromeda (M31) were once moving much faster than in our models. This would allow LG dwarfs to gain very high RVs via gravitational slingshot encounters with a massive fast-moving galaxy. Such a scenario is possible in some modified gravity theories, especially those that require the MW and M31 to have previously undergone a close flyby. In a ΛCDM context, however, this scenario is not feasible as the resulting dynamical friction would cause a rapid merger.

Black holes, anti de Sitter space, and topological strings

NASA Astrophysics Data System (ADS)

Yin, Xi

This thesis is devoted to the study of black holes in string theory, their connection to two and three dimensional anti de-Sitter space, and topological strings. We start by proposing a relation between supersymmetric black holes in four and five dimensions, as well as connections between multi-centered black holes in four dimensions and black rings in five dimensions. This connection is then applied to counting supersymmetric dyonic black holes in four dimensional string compactifications with 16 and 32 supersymmetries, respectively. We then turn to the near horizon attractor geometry AdS 2 x S2 x CY 3, and study the classical supersymmetric D-branes in this background. We also find supersymmetric black hole solutions in supergravity in AdS2 x S2, although the solutions have regions of closed timelike curves. Finally we consider the M-theory attractor geometry AdS3 x S2 x CY3, and compute the elliptic genus of the dual (0, 4) CFT by counting wrapped M2-brane states in the bulk in a dilute gas approximation. This leads to a derivation of the conjectured relation between black hole partition function and topological string amplitudes.

Parallel Logic Programming and Parallel Systems Software and Hardware

DTIC Science & Technology

1989-07-29

Conference, Dallas TX. January 1985. (55) [Rous75] Roussel, P., "PROLOG: Manuel de Reference et d’Uilisation", Group d’ Intelligence Artificielle , Universite d...completed. Tools were provided for software development using artificial intelligence techniques. Al software for massively parallel architectures was...using artificial intelligence tech- niques. Al software for massively parallel architectures was started. 1. Introduction We describe research conducted

Aspects of some dualities in string theory

NASA Astrophysics Data System (ADS)

Kim, Bom Soo

AdS/CFT correspondence in string theory has changed landscape of the theoretical physics. Through this celebrated duality between gravity theory and field theory, one can investigate analytically strongly coupled gauge theories such as Quantum Chromodynamics (QCD) in terms of weakly coupled string theory such as supergravity theory and vice versa. In the first part of this thesis we used this duality to construct a new type of nonlocal field theory, called Puff Field Theory, in terms of D3 branes in type IIB string theory with a geometric twist. In addition to the strong-weak duality of AdS/CFT, there also exists a weak-weak duality, called Twistor String Theory. Twistor technique is successfully used to calculate the SYM scattering amplitude in an elegant fashion. Yet, the progress in the string theory side was hindered by a non-unitary conformal gravity. We extend the Twistor string theory by introducing mass terms, in the second part of the thesis. A chiral mass term is identified as a vacuum expectation value of a conformal supergravity field and is tied with the breaking of the conformal symmetry of gravity. As a prime candidate for a quantum theory of gravity, string theory revealed many promising successes such as counting the number of microstates in supersymmetric Black Holes thermodynamics and resolution of timelike and null singularities, to name a few. Yet, the fundamental string and M-theroy formulations are not yet available. Various string theories without gravity, such as Non-Commutative Open String (NCOS) and Open Membrane (OM) theories, are very nice playground to investigate the fundamental structure of string and M-theory without the complication of gravity. In the last part of the thesis, simpler Non-Relativistic String Theories are constructed and investigated. One important motivation for those theories is related to the connection between Non-Relativistic String Theories and Non-critical String Theories through the bosonization of betagamma CFT.

Beyond dRGT as mimetic massive gravity

NASA Astrophysics Data System (ADS)

Golovnev, Alexey

2018-04-01

An interesting proposal has recently been made to extend massive gravity models beyond dRGT by a disformal transformation of the metric. In this Letter we want to note that it can be viewed as a mimetic extension of dRGT gravity which enormously simplifies the Hamiltonian analysis. In particular, pure gravity sector is equivalent to the usual dRGT gravity coupled to a constrained scalar field. And we also give some comments about possible matter couplings.

Winds of Massive Magnetic Stars: Interacting Fields and Flow

NASA Astrophysics Data System (ADS)

Daley-Yates, S.; Stevens, I. R.

2018-01-01

We present results of 3D numerical simulations of magnetically confined, radiatively driven stellar winds of massive stars, conducted using the astrophysical MHD code Pluto, with a focus on understanding the rotational variability of radio and sub-mm emission. Radiative driving is implemented according to the Castor, Abbott and Klein theory of radiatively driven winds. Many magnetic massive stars posses a magnetic axis which is inclined with respect to the rotational axis. This misalignment leads to a complex wind structure as magnetic confinement, centrifugal acceleration and radiative driving act to channel the circumstellar plasma into a warped disk whose observable properties should be apparent in multiple wavelengths. This structure is analysed to calculate free-free thermal radio emission and determine the characteristic intensity maps and radio light curves.

Unraveling the Chemical Nature of the 3D "Hollow" Hybrid Halide Perovskites.

PubMed

Spanopoulos, Ioannis; Ke, Weijun; Stoumpos, Constantinos C; Schueller, Emily C; Kontsevoi, Oleg Y; Seshadri, Ram; Kanatzidis, Mercouri G

2018-05-02

The newly introduced class of 3D halide perovskites, termed "hollow" perovskites, has been recently demonstrated as light absorbing semiconductor materials for fabricating lead-free perovskite solar cells with enhanced efficiency and superior stability. Hollow perovskites derive from three-dimensional (3D) AMX 3 perovskites ( A = methylammonium (MA), formamidinium (FA); M = Sn, Pb; X = Cl, Br, I), where small molecules such as ethylenediammonium cations ( en) can be incorporated as the dication without altering the structure dimensionality. We present in this work the inherent structural properties of the hollow perovskites and expand this class of materials to the Pb-based analogues. Through a combination of physical and spectroscopic methods (XRD, gas pycnometry, 1 H NMR, TGA, SEM/EDX), we have assigned the general formula (A) 1- x ( en) x (M) 1-0.7 x (X) 3-0.4 x to the hollow perovskites. The incorporation of en in the 3D perovskite structure leads to massive M and X vacancies in the 3D [ MX 3 ] framework, thus the term hollow. The resulting materials are semiconductors with significantly blue-shifted direct band gaps from 1.25 to 1.51 eV for Sn-based perovskites and from 1.53 to 2.1 eV for the Pb-based analogues. The increased structural disorder and hollow nature were validated by single crystal X-ray diffraction analysis as well as pair distribution function (PDF) analysis. Density functional theory (DFT) calculations support the experimental trends and suggest that the observed widening of the band gap is attributed to the massive M and X vacancies, which create a less connected 3D hollow structure. The resulting materials have superior air stability, where in the case of Sn-based hollow perovskites it exceeds two orders of temporal magnitude compared to the conventional full perovskites of MASnI 3 and FASnI 3 . The hollow perovskite compounds pose as a new platform of promising light absorbers that can be utilized in single junction or tandem solar cells.

Massive sulfide exploration models of the Iberian Pyrite Belt Neves Corvo mine region, based in a 3D geological, geophysical and geochemical ProMine study

NASA Astrophysics Data System (ADS)

Inverno, Carlos; Matos, João Xavier; Rosa, Carlos; Mário Castelo-Branco, José; Granado, Isabel; Carvalho, João; João Baptista, Maria; Represas, Patrícia; Pereira, Zélia; Oliveira, Tomás; Araujo, Vitor

2013-04-01

The Iberian Pyrite Belt (IPB) hosts one of the largest concentrations of massive sulfides in the Earth's crust. This highly productive VMS belt contains more than 85 massive sulfide deposits, totalling an estimate of 1600 Mt of massive ore and about 250 Mt of stockwork ore (Leistel et al., 1998; Oliveira et al., 2005; Tornos, 2006). Included in the South Portuguese Zone the IPB is represented by the Phyllite-Quartzite Group (PQG) composed of shales and quartzites of late Devonian age followed by the Volcanic-Sedimentary Complex (VSC) a submarine succession of sediments and felsic and basic volcanic rocks (late Famennian-late Viséan age). Above the IPB a turbidite sedimentary unit occurs being represented by the Baixo Alentejo Flysch Group (BAFG). The ore deposits are hosted by felsic volcanic rocks and sediments that are dominant in the lower part of the VSC succession. The Neves Corvo (ProMine, EU FP7) project area is focused on the Neves Corvo deposit, an active copper mine. The project area is located between the Messejana Fault and the Portuguese/Spanish border which has been selected for the 3D geological and geophysical modelling study, based on high exploration potential of the Neves Corvo area (Oliveira et al. 2006, Relvas et al. 2006, Pereira et al. 2008, Rosa et al. 2008, Matos et al. 2011, Oliveira et al. 2013). In this study existing LNEG and AGC geological, geophysical and geochemistry databases were considered. New surveys were done: i) - A physical volcanology and palynostratigraphic age data study and log of the Cotovio drill-hole core (1,888 m, drilled by AGC). ii) - Interpretation of 280 km of Squid TEM performed by AGC. Based on the TEM data, significant conductors have been identified related with: shallow conductive cover, graphitic shale, black shale and sulphide mineralizations. The most important TEM conductors are related with the Neves Corvo massive sulphides lenses (1-10 Ωm). iii) - Ground and residual gravimetry studies including superficial directional derivatives to obtain the various directions of the late-Variscan faults, the main overthrusts and lithological structures. iv) - Detailed palynological sediment dating; v) - A seismic survey was conducted in the vicinities of the Neves Corvo mine totalling 82 km of profiles with target depth of over 10 km. A 3D regional model has been constructed for the selected IPB area using GoCAD, integrating the most critical information of the follow geological units: the lower unit BAFG Mértola Formation, the VSC, the Neves Corvo ores and the PQG. It incorporated surface regional geological maps, 168 drill-hole geological logs throughout the area, structural and tectonic data, former seismic sections, where available, and a digital terrain model. Chemical data from 42 selected drill-holes in order to outline in 3D the Cu distribution in the area. The results have already indicated new important guidelines for VHMS exploration and new regional correlations with the Neves Corvo mining area. The 3D modelling study was essential to the detail understanding of the complex IPB geological structures observed in the south of Portugal.

δ18O and δD variations in Holocene massive ice in the Sabettayakha river mouth, northern Yamal Peninsula

NASA Astrophysics Data System (ADS)

Vasil'chuk, Yu. K.; Podborny, Ye. Ye.; Budantseva, N. A.; Vasil'chuk, A. C.; Sullina, A. N.; Chizhova, Ju. N.

2016-10-01

The conditions of formation of massive ice near the South Tambey gas-condensate field in northern Yamal Peninsula are studied. It is shown that massive ice bodies up to 4.5 m thick occur in the Holocene deposits of the high laida and the first terrace. Therefore, they cannot be the remains of glaciers; they are ground ice formations. All three types of massive ice have quite various isotopic compositions: the values of δD range from-107 to-199.7, and δ18O from-15.7 to-26.48‰. Such a significant differentiation in isotopic composition is a result of cryogenic fractionation in a freezing water-saturated sediment. The most negative isotope values are even lower in this Holocene massive ice than in the Late Pleistocene ice-wedge ice of Yamal Peninsula.

CANDELS Sheds Light on the Environmental Quenching of Low-mass Galaxies

NASA Astrophysics Data System (ADS)

Guo, Yicheng; Bell, Eric F.; Lu, Yu; Koo, David C.; Faber, S. M.; Koekemoer, Anton M.; Kurczynski, Peter; Lee, Seong-Kook; Papovich, Casey; Chen, Zhu; Dekel, Avishai; Ferguson, Henry C.; Fontana, Adriano; Giavalisco, Mauro; Kocevski, Dale D.; Nayyeri, Hooshang; Pérez-González, Pablo G.; Pforr, Janine; Rodríguez-Puebla, Aldo; Santini, Paola

2017-06-01

We investigate the environmental quenching of galaxies, especially those with stellar masses (M *) < 109.5 M ⊙, beyond the local universe. Essentially all local low-mass quenched galaxies (QGs) are believed to live close to massive central galaxies, which is a demonstration of environmental quenching. We use CANDELS data to test whether or not such a dwarf QG-massive central galaxy connection exists beyond the local universe. For this purpose, we only need a statistically representative, rather than complete, sample of low-mass galaxies, which enables our study to z ≳ 1.5. For each low-mass galaxy, we measure the projected distance (d proj) to its nearest massive neighbor (M * > 1010.5 M ⊙) within a redshift range. At a given z and M *, the environmental quenching effect is considered to be observed if the d proj distribution of QGs ({d}{proj}Q) is significantly skewed toward lower values than that of star-forming galaxies ({d}{proj}{SF}). For galaxies with 108 M ⊙ < M * < 1010 M ⊙, such a difference between {d}{proj}Q and {d}{proj}{SF} is detected up to z ˜ 1. Also, about 10% of the quenched galaxies in our sample are located between two and four virial radii (R Vir) of the massive halos. The median projected distance from low-mass QGs to their massive neighbors, {d}{proj}Q/{R}{Vir}, decreases with satellite M * at M * ≲ 109.5 M ⊙, but increases with satellite M * at M * ≳ 109.5 M ⊙. This trend suggests a smooth, if any, transition of the quenching timescale around M * ˜ 109.5 M ⊙ at 0.5 < z < 1.0.

Gravity on-shell diagrams

DOE PAGES

Herrmann, Enrico; Trnka, Jaroslav

2016-11-22

Here, we study on-shell diagrams for gravity theories with any number of super-symmetries and find a compact Grassmannian formula in terms of edge variables of the graphs. Unlike in gauge theory where the analogous form involves only d log-factors, in gravity there is a non-trivial numerator as well as higher degree poles in the edge variables. Based on the structure of the Grassmannian formula for N = 8 supergravity we conjecture that gravity loop amplitudes also possess similar properties. In particular, we find that there are only logarithmic singularities on cuts with finite loop momentum and that poles at infinitymore » are present, in complete agreement with the conjecture presented in.« less

Dimensional reduction as a method to obtain dual theories for massive spin two in arbitrary dimensions

NASA Astrophysics Data System (ADS)

Khoudeir, A.; Montemayor, R.; Urrutia, Luis F.

2008-09-01

Using the parent Lagrangian method together with a dimensional reduction from D to (D-1) dimensions, we construct dual theories for massive spin two fields in arbitrary dimensions in terms of a mixed symmetry tensor TA[A1A2…AD-2]. Our starting point is the well-studied massless parent action in dimension D. The resulting massive Stueckelberg-like parent actions in (D-1) dimensions inherit all the gauge symmetries of the original massless action and can be gauge fixed in two alternative ways, yielding the possibility of having a parent action with either a symmetric or a nonsymmetric Fierz-Pauli field eAB. Even though the dual sector in terms of the standard spin two field includes only the symmetrical part e{AB} in both cases, these two possibilities yield different results in terms of the alternative dual field TA[A1A2…AD-2]. In particular, the nonsymmetric case reproduces the Freund-Curtright action as the dual to the massive spin two field action in four dimensions.

Macroscopic theory of dark sector

NASA Astrophysics Data System (ADS)

Meierovich, Boris

A simple Lagrangian with squared covariant divergence of a vector field as a kinetic term turned out an adequate tool for macroscopic description of the dark sector. The zero-mass field acts as the dark energy. Its energy-momentum tensor is a simple additive to the cosmological constant [1]. Space-like and time-like massive vector fields describe two different forms of dark matter. The space-like massive vector field is attractive. It is responsible for the observed plateau in galaxy rotation curves [2]. The time-like massive field displays repulsive elasticity. In balance with dark energy and ordinary matter it provides a four parametric diversity of regular solutions of the Einstein equations describing different possible cosmological and oscillating non-singular scenarios of evolution of the universe [3]. In particular, the singular big bang turns into a regular inflation-like transition from contraction to expansion with the accelerate expansion at late times. The fine-tuned Friedman-Robertson-Walker singular solution corresponds to the particular limiting case at the boundary of existence of regular oscillating solutions in the absence of vector fields. The simplicity of the general covariant expression for the energy-momentum tensor allows to analyse the main properties of the dark sector analytically and avoid unnecessary model assumptions. It opens a possibility to trace how the additional attraction of the space-like dark matter, dominating in the galaxy scale, transforms into the elastic repulsion of the time-like dark matter, dominating in the scale of the Universe. 1. B. E. Meierovich. "Vector fields in multidimensional cosmology". Phys. Rev. D 84, 064037 (2011). 2. B. E. Meierovich. "Galaxy rotation curves driven by massive vector fields: Key to the theory of the dark sector". Phys. Rev. D 87, 103510, (2013). 3. B. E. Meierovich. "Towards the theory of the evolution of the Universe". Phys. Rev. D 85, 123544 (2012).

Tribrid Inflation in Supergravity

NASA Astrophysics Data System (ADS)

Antusch, Stefan; Dutta, Koushik; Kostka, Philipp M.

We propose a novel class of F-term hybrid inflation models in supergravity (SUGRA) where the η-problem is resolved using either a Heisenberg symmetry or a shift symmetry of the Kähler potential. In addition to the inflaton and the waterfall field, this class (referred to as tribrid inflation) contains a third "driving" field which contributes the large vacuum energy during inflation by its F-term. In contrast to the "standard" hybrid scenario, it has several attractive features due to the property of vanishing inflationary superpotential (Winf = 0) during inflation. Quantum corrections induced by symmetry breaking terms in the superpotential generate a slope of the potential and lead to a spectral tilt consistent with recent WMAP observations.

Sneutrino driven GUT inflation in supergravity

NASA Astrophysics Data System (ADS)

Gonzalo, Tomás E.; Heurtier, Lucien; Moursy, Ahmad

2017-06-01

In this paper, we embed the model of flipped GUT sneutrino inflation — in a flipped SU(5) or SO(10) set up — developed by Ellis et al. in a supergravity framework. The GUT symmetry is broken by a waterfall which could happen at early or late stage of the inflationary period. The full field dynamics is thus studied in detail and these two main inflationary configurations are exposed, whose cosmological predictions are both in agreement with recent astrophysical measurements. The model has an interesting feature where the inflaton has natural decay channels to the MSSM particles allowed by the GUT gauge symmetry. Hence it can account for the reheating after the inflationary epoch.

Modified classification and single-stage microsurgical repair of posttraumatic infected massive bone defects in lower extremities.

PubMed

Yang, Yun-fa; Xu, Zhong-he; Zhang, Guang-ming; Wang, Jian-wei; Hu, Si-wang; Hou, Zhi-qi; Xu, Da-chuan

2013-11-01

Posttraumatic infected massive bone defects in lower extremities are difficult to repair because they frequently exhibit massive bone and/or soft tissue defects, serious bone infection, and excessive scar proliferation. This study aimed to determine whether these defects could be classified and repaired at a single stage. A total of 51 cases of posttraumatic infected massive bone defect in lower extremity were included in this study. They were classified into four types on the basis of the conditions of the bone defects, soft tissue defects, and injured limb length, including Type A (without soft tissue defects), Type B (with soft tissue defects of 10 × 20 cm or less), Type C (with soft tissue defects of 10 × 20 cm or more), and Type D (with the limb shortening of 3 cm or more). Four types of single-stage microsurgical repair protocols were planned accordingly and implemented respectively. These protocols included the following: Protocol A, where vascularized fibular graft was implemented for Type A; Protocol B, where vascularized fibular osteoseptocutaneous graft was implemented for Type B; Protocol C, where vascularized fibular graft and anterior lateral thigh flap were used for Type C; and Protocol D, where limb lengthening and Protocols A, B, or C were used for Type D. There were 12, 33, 4, and 2 cases of Types A, B, C, and D, respectively, according to this classification. During the surgery, three cases of planned Protocol B had to be shifted into Protocol C; however, all microsurgical repairs were completed. With reference to Johner-Wruhs evaluation method, the total percentage of excellent and good results was 82.35% after 6 to 41 months of follow-up. It was concluded that posttraumatic massive bone defects could be accurately classified into four types on the basis of the conditions of bone defects, soft tissue coverage, and injured limb length, and successfully repaired with the single-stage repair protocols after thorough debridement. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Bulk and boundary unitary gravity in 3D: MMG2

NASA Astrophysics Data System (ADS)

Tekin, Bayram

2015-07-01

We construct a massive spin-2 theory in 2 +1 dimensions that is immune to the bulk-boundary unitarity conflict in anti-de Sitter space and hence amenable to holography. The theory is an extension of topologically massive gravity (TMG), just like the recently found minimal massive gravity (MMG), but it has two massive helicity modes instead of a single one. The theory admits all the solutions of TMG with a redefined topological parameter. We calculate the Shapiro time delay and show that flat-space (local) causality is not violated. We show that there is an interesting relation between the theory we present here (which we call MMG2 ), MMG, and the earlier new massive gravity (NMG): namely, field equations of these theories are nontrivially related. We study the bulk excitations and boundary charges of the conformal field theory that could be dual to gravity. We also find the chiral gravity limit for which one of the massive modes becomes massless. The virtue of the model is that one does not have to go to the chiral limit to achieve unitarity in the bulk and on the boundary, and the log-terms that appear in the chiral limit and cause instability do not exist in the generic theory.

T -folds from Yang-Baxter deformations

NASA Astrophysics Data System (ADS)

Fernández-Melgarejo, José J.; Sakamoto, Jun-ichi; Sakatani, Yuho; Yoshida, Kentaroh

2017-12-01

Yang-Baxter (YB) deformations of type IIB string theory have been well studied from the viewpoint of classical integrability. Most of the works, however, are focused upon the local structure of the deformed geometries and the global structure still remains unclear. In this work, we reveal a non-geometric aspect of YB-deformed backgrounds as T -fold by explicitly showing the associated O( D, D; ℤ) T -duality monodromy. In particular, the appearance of an extra vector field in the generalized supergravity equations (GSE) leads to the non-geometric Q-flux. In addition, we study a particular solution of GSE that is obtained by a non-Abelian T-duality but cannot be expressed as a homogeneous YB deformation, and show that it can also be regarded as a T -fold. This result indicates that solutions of GSE should be non-geometric quite in general beyond the YB deformation.

Three-Dimensional Nanobiocomputing Architectures With Neuronal Hypercells

DTIC Science & Technology

2007-06-01

Neumann architectures, and CMOS fabrication. Novel solutions of massive parallel distributed computing and processing (pipelined due to systolic... and processing platforms utilizing molecular hardware within an enabling organization and architecture. The design technology is based on utilizing a...Microsystems and Nanotechnologies investigated a novel 3D3 (Hardware Software Nanotechnology) technology to design super-high performance computing

Large scale magnetic fields from torsion modes and massive photon inflation

NASA Astrophysics Data System (ADS)

Garcia de Andrade, L. C.

2017-10-01

Previously, Barrow and Tsagas (2008 Phys. Rev. D 77 107302) showed that a slower decay of magnetic fields are present in open Friedmann universes, with traditional Maxwell equations. In their paper magnetic fields of the order of B˜ 10-33~G , which are far below the value required to seed galactic dynamos, were obtained. In this paper, galactic dynamo seeds of the order of B˜ 10-23~G are obtained from massive electrodynamics in an Einstein-Cartan-Proca expanding universe of de Sitter type. Slow decay of magnetic fields in photon-torsion coupling in quantum electrodynamics (Garcia de Andrade 2011 Phys. Lett. B 468 28) have been recently shown by the author Garcia de Andrade (2012 Phys. Lett. B 711 143) to also not be able to seed galactic dynamos. Torsion modes are constrained by the field equations. Spacetime torsion is shown to be explicitly responsible for the slow decay of a cosmic magnetic field. In the absence of massive photon torsion coupling the magnetic field decay is of the order B˜ t-\\frac{3{2}} , when torsion turns on B˜ t-1.2 . The pure massive-photon-torsion contribution amplifies the magnetic field by B_torsion˜ t0.1 which characterizes an extremely slow magnetic dynamo action due to purely torsion gravitational effects. Recently Barrow, Tsagas and Yamamoto (2012 Phys. Rev. D 86 023535) have obtained superadiabatic amplification of B-fields in Friedmann open cosmology which lies within {10-20~G} and 10-12~G which falls very comfortably within the limits to seed galactic dynamos. The are other simple solutions where a B-field decays as B˜ a-1 , a relatively weak photon-torsion coupling approximation. These solutions are obtained for de Sitter and Friedmann metrics. Numerical values as displayed in this new version of the paper specifically for GUT phases of inflation with and without massive photons; without photons we obtain the well known value of GR which is B_GUT˜ 1048~G while for the values with massive photons one obtains B_GUT/γ˜ 10-3.5Gauss . At the present time one obtains B_today≤slant{10-21.6~G} and with massive photons one obtains B_today/γ˜ 10-1.8~G , which is unfortunately much stronger than the value obtained by astronomical observations of 10-9~G .

Translation invariant time-dependent solutions to massive gravity II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mourad, J.; Steer, D.A., E-mail: mourad@apc.univ-paris7.fr, E-mail: steer@apc.univ-paris7.fr

2014-06-01

This paper is a sequel to JCAP 12 (2013) 004 and is also devoted to translation-invariant solutions of ghost-free massive gravity in its moving frame formulation. Here we consider a mass term which is linear in the vielbein (corresponding to a β{sub 3} term in the 4D metric formulation) in addition to the cosmological constant. We determine explicitly the constraints, and from the initial value formulation show that the time-dependent solutions can have singularities at a finite time. Although the constraints give, as in the β{sub 1} case, the correct number of degrees of freedom for a massive spin twomore » field, we show that the lapse function can change sign at a finite time causing a singular time evolution. This is very different to the β{sub 1} case where time evolution is always well defined. We conclude that the β{sub 3} mass term can be pathological and should be treated with care.« less

Infrared propagators of Yang-Mills theory from perturbation theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tissier, Matthieu; Wschebor, Nicolas

2010-11-15

We show that the correlation functions of ghosts and gluons for the pure Yang-Mills theory in Landau gauge can be accurately reproduced for all momenta by a one-loop calculation. The key point is to use a massive extension of the Faddeev-Popov action. The agreement with lattice simulation is excellent in d=4. The one-loop calculation also reproduces all the characteristic features of the lattice simulations in d=3 and naturally explains the peculiarities of the propagators in d=2.

Thyrotoxicosis after a massive levothyroxine ingestion in a 3-year-old patient.

PubMed

Hays, Hannah L; Jolliff, Heath A; Casavant, Marcel J

2013-11-01

Most children with exploratory levothyroxine ingestions remain asymptomatic or suffer only minor effects, and most patients can be managed in the home or with supportive care in the hospital. We present a case of a 3-year-old girl who was found after a witnessed massive ingestion of levothyroxine. The patient was initially seen in an emergency department and discharged in stable condition, only to return 4 days after ingestion with thyrotoxicosis, hypertension, tachycardia, 24 hours of persistent vomiting, and clinical and laboratory evidence of dehydration. On the day of hospital admission, her thyroid-stimulating hormone was 0.018 µIU/mL (reference range, 0.6-4.5 µIU/mL); free T4 (tetraiodothyronine) was greater than 6.0 ng/dL (reference range, 0.7-2.1 ng/dL); and T3 (triiodothyronine) total was 494 ng/dL (reference range, 100-200 ng/dL). During a 3-day hospital admission, she was managed with supportive care, including intravenous fluid rehydration and antiemetics, and was ultimately discharged in good condition. The patient was followed up until 2 months after ingestion and remained asymptomatic. Although most exploratory levothyroxine ingestions suffer little to no clinical effects, serious symptoms can occur. Because serious symptoms can occur in a delayed fashion, it is important for clinicians to give proper anticipatory guidance regarding home symptom monitoring, follow-up, and reasons to return to the emergency department when patients present for medical evaluation.

Scaling relations and the fundamental line of the local group dwarf galaxies

NASA Astrophysics Data System (ADS)

Woo, Joanna; Courteau, Stéphane; Dekel, Avishai

2008-11-01

We study the scaling relations between global properties of dwarf galaxies in the local group. In addition to quantifying the correlations between pairs of variables, we explore the `shape' of the distribution of galaxies in log parameter space using standardized principal component analysis, the analysis is performed first in the 3D structural parameter space of stellar mass M*, internal velocity V and characteristic radius R* (or surface brightness μ*). It is then extended to a 4D space that includes a stellar population parameter such as metallicity Z or star formation rate . We find that the local group dwarfs basically define a one-parameter `fundamental line' (FL), primarily driven by stellar mass, M*. A more detailed inspection reveals differences between the star formation properties of dwarf irregulars (dI's) and dwarf ellipticals (dE's), beyond the tendency of the latter to be more massive. In particular, the metallicities of dI's are typically lower by a factor of 3 at a given M* and they grow faster with increasing M*, showing a tighter FL in the 4D space for the dE's. The structural scaling relations of dI's resemble those of the more massive spirals, but the dI's have lower star formation rates for a given M* which also grow faster with increasing M*. On the other hand, the FL of the dE's departs from the fundamental plane of bigger ellipticals. While the one-parameter nature of the FL and the associated slopes of the scaling relations are consistent with the general predictions of supernova feedback from Dekel & Woo, the differences between the FL's of the dE's and the dI's remain a challenge and should serve as a guide for the secondary physical processes responsible for these two types.

Aspects of T-Dually Extended Superspaces

NASA Astrophysics Data System (ADS)

Polacek, Martin

This dissertation is divided into three main parts where we derive various properties of the T-dually extended superspaces. In the first part we reformulate the manifestly T-dual description of the massless sector of the closed bosonic string, directly from the geometry associated with the (left and right) affine Lie algebra of the coset space Poincare/Lorentz. This construction initially doubles not only the (space-time) coordinates for translations but also those for Lorentz transformations (and their "dual"). As a result, the Lorentz connection couples directly to the string (as does the vielbein), rather than being introduced indirectly through covariant derivatives as previously. This not only reproduces the old definition of T-dual torsion, but automatically gives a general, covariant definition of T-dual curvature (but still with some undetermined connections). In the second part we give the manifestly T-dual formulation of the massless sector of the classical 3D Type II superstring in off-shell 3D N = 2 superspace, including the action. It has a simple relation to the known superspace of 4D N = 1 supergravity in 4D M-theory via 5D F-theory. The pre-potential appears as part of the vielbein, without derivatives. In the last and the most involved part we find the pre-potential in the superspace with AdS5 x S5 background. The pre-potential appears as part of the vielbeins, without derivatives. In both subspaces (AdS5 and S 5) we use Poincare coordinates. We pick one bulk coordinate in AdS5 and one bulk coordinate in S 5 to define the space-cone gauge. Such space-cone gauge destroys the bulk Lorentz covariance. However, it still preserves boundary Lorentz covariance (and gives projective superspace) SO ( 3, 1) ⊗ SO (4) and so symmetries of boundary CFT are manifest.

Introduction to the AdS/CFT Correspondence

NASA Astrophysics Data System (ADS)

Nąstase, Horaǧiu

2015-09-01

Preface; Introduction; Part I. Background: 1. Elements of quantum field theory and gauge theory; 2. Basics of general relativity. Anti-de Sitter space; 3. Basics of supersymmetry; 4. Basics of supergravity; 5. Kaluza-Klein dimensional reduction; 6. Black holes and p-branes; 7. String theory actions and spectra; 8. Elements of conformal field theory; 9. D-branes; Part II. Basics of AdS/CFT for N = 4 SYM vs AdS5 × S5: 10. The AdS/CFT correspondence: motivation, definition and spectra; 11. Witten prescription and 3-point correlator calculations; 12. Holography in Lorentzian signature: Poincaré and global; 13. Solitonic objects in AdS/CFT; 14. Quarks and the Wilson loop; 15. Finite temperature and N = 4 SYM plasmas; 16. Scattering processes and gravitational shockwave limit; 17. The pp-wave correspondence; 18. Spin chains; Part III. AdS/CFT Developments and Gauge-Gravity Dualities: 19. Other conformal cases; 20. The 3 dimensional ABJM model vs. AdS4 × CP3; 21. Gravity duals; 22. Holographic renormalization; 23. RG flow between fixed points; 24. Phenomenological gauge-gravity duality I: AdS/QCD; 25. Phenomenological gauge-gravity duality II: AdS/CMT; 26. Gluon scattering: the Alday-Maldacena prescription; 27. Holographic entanglement entropy: the Ryu-Takayanagi prescription.

Outer Electrospun Polycaprolactone Shell Induces Massive Foreign Body Reaction and Impairs Axonal Regeneration through 3D Multichannel Chitosan Nerve Guides

PubMed Central

Behrens, Peter; Wienecke, Soenke; Chakradeo, Tanmay; Glasmacher, Birgit

2014-01-01

We report on the performance of composite nerve grafts with an inner 3D multichannel porous chitosan core and an outer electrospun polycaprolactone shell. The inner chitosan core provided multiple guidance channels for regrowing axons. To analyze the in vivo properties of the bare chitosan cores, we separately implanted them into an epineural sheath. The effects of both graft types on structural and functional regeneration across a 10 mm rat sciatic nerve gap were compared to autologous nerve transplantation (ANT). The mechanical biomaterial properties and the immunological impact of the grafts were assessed with histological techniques before and after transplantation in vivo. Furthermore during a 13-week examination period functional tests and electrophysiological recordings were performed and supplemented by nerve morphometry. The sheathing of the chitosan core with a polycaprolactone shell induced massive foreign body reaction and impairment of nerve regeneration. Although the isolated novel chitosan core did allow regeneration of axons in a similar size distribution as the ANT, the ANT was superior in terms of functional regeneration. We conclude that an outer polycaprolactone shell should not be used for the purpose of bioartificial nerve grafting, while 3D multichannel porous chitosan cores could be candidate scaffolds for structured nerve grafts. PMID:24818158

Outer electrospun polycaprolactone shell induces massive foreign body reaction and impairs axonal regeneration through 3D multichannel chitosan nerve guides.

PubMed

Duda, Sven; Dreyer, Lutz; Behrens, Peter; Wienecke, Soenke; Chakradeo, Tanmay; Glasmacher, Birgit; Haastert-Talini, Kirsten

2014-01-01

We report on the performance of composite nerve grafts with an inner 3D multichannel porous chitosan core and an outer electrospun polycaprolactone shell. The inner chitosan core provided multiple guidance channels for regrowing axons. To analyze the in vivo properties of the bare chitosan cores, we separately implanted them into an epineural sheath. The effects of both graft types on structural and functional regeneration across a 10 mm rat sciatic nerve gap were compared to autologous nerve transplantation (ANT). The mechanical biomaterial properties and the immunological impact of the grafts were assessed with histological techniques before and after transplantation in vivo. Furthermore during a 13-week examination period functional tests and electrophysiological recordings were performed and supplemented by nerve morphometry. The sheathing of the chitosan core with a polycaprolactone shell induced massive foreign body reaction and impairment of nerve regeneration. Although the isolated novel chitosan core did allow regeneration of axons in a similar size distribution as the ANT, the ANT was superior in terms of functional regeneration. We conclude that an outer polycaprolactone shell should not be used for the purpose of bioartificial nerve grafting, while 3D multichannel porous chitosan cores could be candidate scaffolds for structured nerve grafts.

Successful treatment of massive ascites due to lupus peritonitis with hydroxychloroquine in old- onset lupus erythematosus.

PubMed

Hammami, Sonia; Bdioui, Fethia; Ouaz, Afef; Loghmari, Hichem; Mahjoub, Sylvia; Saffar, Hamouda

2014-01-01

Systemic lupus erythematous (SLE) is an auto-immune disease with multiple organ involvements that occurs mainly in young women. Literature data suggest that serositis is more frequent in late-onset SLE. However, peritoneal serositis with massive ascites is an extremely rare manifestation. We report a case of old-onset lupus peritonitis treated successfully by Hydroxychloroquine. A 77-year-old Tunisian woman was hospitalized because of massive painful ascites. Her family history did not include any autoimmune disease. She was explored 4 years prior to admission for exudative pleuritis of the right lung without any established diagnosis. Physical examination showed only massive ascites. Laboratory investigations showed leucopenia: 3100/mm3, lymphopenia: 840/mm3 and trace protein (0.03 g/24 h). Ascitic fluid contained 170 cells mm(3) (67% lymphocytes), 46 g/L protein, but no malignant cells. The main etiologies of exudative ascites were excluded. She had markedly elevated anti-nuclear antibody (ANA) titer of 1/1600 and a significantly elevated titer of antibody to double-stranded DNA (83 IU/mL) with hypo-complementemia (C3 levl was at 67 mg/dL). Antibody against the Smith antigen was also positive. Relying on these findings, the patient was diagnosed with SLE and treated with Hydroxychloroquine 200 mg daily in combination with diuretics. One month later, there was no detectable ascitic fluid and no pleural effusions. Five months later she remained free from symptoms while continuing to take chloroquine. This case was characterized by old age of onset of SLE, the extremely rare initial presentation with lupus peritonitis and massive painful ascites with dramatic response to only hydroxychloroquine treatment.

Hα imaging observations of early-type galaxies from the ATLAS3D survey

NASA Astrophysics Data System (ADS)

Gavazzi, G.; Consolandi, G.; Pedraglio, S.; Fossati, M.; Fumagalli, M.; Boselli, A.

2018-03-01

Context. The traditional knowledge of the mechanisms that brought to the formation and evolution of early type galaxies (ETG) in a hierarchical Universe was challenged by the unexpected finding by ATLAS3D that 86% ETGs show signs of a fast rotating disk at their interior, implying an origin common to most spiral galaxies, followed by a quenching phase, while only a minority of the most massive systems are slow rotators and were likely to be the products of merger events. Aims: Our aim is to improve our knowledge on the content and distribution of ionised hydrogen and their usage to form stars in a representative sample of ETGs for which the kinematics and detailed morphological classification were known from ATLAS3D. Methods: Using narrow-band filters centered on the redshifted Hα line along with a broad-band (r-Gunn) filter to recover the stellar continuum, we observed or collected existing imaging observations for 147 ETG (including members of the Virgo cluster), representative of the whole ATLAS3D survey. Results: 55 ETGs (37%) were detected in the Hα line above our detection threshold (HαEW ≤ -1 Å) and 21 harbour a strong source (HαEW ≤ -5 Å) . Conclusions: The strong Hα emitters appear associated with mostly low-mass (M* 1010 M⊙) S0 galaxies which contain conspicuous stellar and gaseous disks, harbouring significant star formation at their interior, including their nuclei. The weak Hα emitters are almost one order of magnitude more massive, contain gas-poor disks and harbour an AGN at their centers. Their emissivity is dominated by [NII] and does not imply star formation. The 92 undetected ETGs constitute the majority in our sample and are gas-free systems which lack a disk and exhibit passive spectra even in their nuclei. These pieces of evidence reinforce the conclusion of Cappellari (2016, ARA&A, 54, 597) that the evolution of ETGs followed the secular channel for the less massive systems and the dry merging channel for the most massive galaxies at the center of clusters of galaxies. Based on observations taken at the Mexican Observatorio Astronomico Nacional and at the Loiano telescope belonging to the Bologna Observatory.Tables A.1-A.6 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/611/A28

New massive gravity and AdS(4) counterterms.

PubMed

Jatkar, Dileep P; Sinha, Aninda

2011-04-29

We show that the recently proposed Dirac-Born-Infeld extension of new massive gravity emerges naturally as a counterterm in four-dimensional anti-de Sitter space (AdS(4)). The resulting on-shell Euclidean action is independent of the cutoff at zero temperature. We also find that the same choice of counterterm gives the usual area law for the AdS(4) Schwarzschild black hole entropy in a cutoff-independent manner. The parameter values of the resulting counterterm action correspond to a c=0 theory in the context of the duality between AdS(3) gravity and two-dimensional conformal field theory. We rewrite this theory in terms of the gauge field that is used to recast 3D gravity as a Chern-Simons theory.

Magnetic structure of Basse-Terre volcanic island (Guadeloupe, Lesser Antilles) inferred from 3D inversion of aeromagnetic data

NASA Astrophysics Data System (ADS)

Barnoud, Anne; Bouligand, Claire; Coutant, Olivier; Carlut, Julie

2017-12-01

We interpret aeromagnetic data to constrain the magnetic structure of the island of Basse-Terre, Guadeloupe, Lesser Antilles. Aeromagnetic data are inverted in the spatial domain with a Bayesian formulation to retrieve the 3D distribution of rock magnetization intensity and polarity. The inversion is regularized using a correlation length and standard deviation for magnetization chosen to be consistent with results from paleomagnetic measurements on lava flow samples from Basse-Terre. The resulting 3D model of magnetization is consistent at the surface with observed polarities and at depth with a 2D model obtained from a Parker and Huestis (1974) inversion in the Fourier domain. The inferred magnetic structure is compared with the available geological information deduced from published geological, geomorphological and geochronological studies. In the southern part of the island, very low magnetization is observed around the Soufrière lava dome, last activity of the Grande-Découverte-Carmichaël-Soufrière composite volcano, in relation with a high level of hydrothermal alteration. High-magnetizations in the South-East might reflect the presence of massive lava flows and lava domes from the Madeleine vents and Monts Caraïbes. Medium magnetizations in the South-West coincide with the location of debris avalanche deposits associated with the collapse of the former Carmichaël volcano and might reflect less massive lava structure at depth. Using the volume of normal polarity in the South part of Basse-Terre recovered in our 3D model of rock magnetization, we estimate an average construction rate of ∼ 9.4 ×10-4 km3/yr during the Brunhes chron which provides new insights on the volcanic activity of La Soufrière volcano.

Can very high level of D-dimer exclusively predict the presence of thromboembolic diseases?

PubMed

Ho, Chao-Hung

2011-04-01

D-dimer quantitative test is mainly used to rule out the presence of thromboembolic diseases (TEDs). Whether very high D-dimer (100 times above the cutoff point) can exclusively indicate the presence of TED should be known. D-dimer was detected by a quantitative immunoturbidimetric assay. The normal value is 0.2-0.7 mg/L fibrinogen equivalent units (FEUs). During the year of 2009, 1,053 D-dimer tests were performed. We analyzed the results of these patients to find out the causes of very high D-dimer. The mean value of D-dimer in the 1,053 tests was 8.56 mg/L FEU, ranging from <0.2 mg/L to 563.2 mg/L FEU. Of them, 28 samples from 21 patients had very high D-dimer value: >50 mg/L FEU. Of the 21 patients, 9 (43%) had TED, 1 had suspected TED, but not proved by computed tomographic (CT) angiogram, 3 had massive gastrointestinal or other site bleeding, 3 patients had cardiac arrest with samples taken immediately after recovery from cardiopulmonary resuscitation (CPR), 2 had sepsis with disseminated intravascular coagulation (DIC), 1 had postpartum hemolysis, elevated liver enzymes, low platelets (HELLP) syndrome with acute pulmonary edema and renal failure, 1 had multiple traumatic injury, and 1 received thrombolytic therapy. Although TED was the most frequently seen disorder in patients with very high D-dimer value, very high D-dimer was not necessary exclusively the marker of TED. Other disorders such as massive bleeding, status post CPR, sepsis with DIC, multiple traumatic injuries, hyperfibrinolysis and HELLP syndrome can also have very high D-dimer. Copyright © 2011. Published by Elsevier B.V.

Vector curvaton with varying kinetic function

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dimopoulos, Konstantinos; Karciauskas, Mindaugas; Wagstaff, Jacques M.

2010-01-15

A new model realization of the vector curvaton paradigm is presented and analyzed. The model consists of a single massive Abelian vector field, with a Maxwell-type kinetic term. By assuming that the kinetic function and the mass of the vector field are appropriately varying during inflation, it is shown that a scale-invariant spectrum of superhorizon perturbations can be generated. These perturbations can contribute to the curvature perturbation of the Universe. If the vector field remains light at the end of inflation it is found that it can generate substantial statistical anisotropy in the spectrum and bispectrum of the curvature perturbation.more » In this case the non-Gaussianity in the curvature perturbation is predominantly anisotropic, which will be a testable prediction in the near future. If, on the other hand, the vector field is heavy at the end of inflation then it is demonstrated that particle production is approximately isotropic and the vector field alone can give rise to the curvature perturbation, without directly involving any fundamental scalar field. The parameter space for both possibilities is shown to be substantial. Finally, toy models are presented which show that the desired variation of the mass and kinetic function of the vector field can be realistically obtained, without unnatural tunings, in the context of supergravity or superstrings.« less

General relativistic effects in the structure of massive white dwarfs

NASA Astrophysics Data System (ADS)

Carvalho, G. A.; Marinho, R. M.; Malheiro, M.

2018-04-01

In this work we investigate the structure of white dwarfs using the Tolman-Oppenheimer-Volkoff equations and compare our results with those obtained from Newtonian equations of gravitation in order to put in evidence the importance of general relativity (GR) for the structure of such stars. We consider in this work for the matter inside white dwarfs two equations of state, frequently found in the literature, namely, the Chandrasekhar and Salpeter equations of state. We find that using Newtonian equilibrium equations, the radii of massive white dwarfs (M>1.3M_{⊙ }) are overestimated in comparison with GR outcomes. For a mass of 1.415M_{⊙ } the white dwarf radius predicted by GR is about 33% smaller than the Newtonian one. Hence, in this case, for the surface gravity the difference between the general relativistic and Newtonian outcomes is about 65%. We depict the general relativistic mass-radius diagrams as M/M_{⊙ }=R/(a+bR+cR^2+dR^3+kR^4), where a, b, c and d are parameters obtained from a fitting procedure of the numerical results and k=(2.08× 10^{-6}R_{⊙ })^{-1}, being R_{⊙ } the radius of the Sun in km. Lastly, we point out that GR plays an important role to determine any physical quantity that depends, simultaneously, on the mass and radius of massive white dwarfs.

First photometric analysis of magnetic activity and orbital period variations for the semi-detached binary BU Vulpeculae

NASA Astrophysics Data System (ADS)

Wang, Jingjing; Zhang, Bin; Yu, Jing; Liu, Liang; Tian, Xiaoman

2018-06-01

Four sets of multi-color CCD photometric observations of the close binary BU Vul were carried out for four successive months in 2010. From our observations, there are obvious variations and asymmetry of light curves on the timescale of a month, indicating high-level stellar spot activity on the surface of at least one component. The Wilson-Devinney (2010) program was used to determine the photometric solutions, which suggest that BU Vul is a semi-detached binary with the cool, less massive component filling with the critical Roche lobe. The solutions also reveal that the spots on the primary and the secondary have changed and drifted in 2010 July, August, and September. Based on analysis of the O - C curves of BU Vul, its orbital period shows a cyclic oscillation (T3 = 22.4 yr, A3 = 0.0029 d) superimposed on a secular increase. The continuous increase is possibly a result of mass transfer from the less massive component to the more massive one at a rate of dM/dt = -2.95 × 10-9 M⊙ yr-1. The cyclic variation maybe be caused by the presence of a tertiary companion with extremely low luminosity. Combined with the distortions of the light curve on 2009 November 4, we infer that BU Vul has two additional companions in a quadruple system.

The Morphological Evolution, AGN Fractions, Dust Content, Environments, and Downsizing of Massive Green Valley Galaxies at 0.5 < z < 2.5 in 3D-HST/CANDELS

NASA Astrophysics Data System (ADS)

Gu, Yizhou; Fang, Guanwen; Yuan, Qirong; Cai, Zhenyi; Wang, Tao

2018-03-01

To explore the evolutionary connection among red, green, and blue galaxy populations, based on a sample of massive ({M}* > {10}10 {M}ȯ ) galaxies at 0.5 < z < 2.5 in five 3D-HST/CANDELS fields, we investigate the dust content, morphologies, structures, active galactic nucleus (AGN) fractions, and environments of these three populations. Green valley galaxies are found to have intermediate dust attenuation and reside in the middle of the regions occupied by quiescent and star-forming galaxies in the UVJ diagram. Compared with blue and red galaxy populations at z < 2, green galaxies have intermediate compactness and morphological parameters. The above findings seem to favor the scenario that green galaxies are at a transitional phase when star-forming galaxies are being quenched into quiescent status. The green galaxies at z < 2 show the highest AGN fraction, suggesting that AGN feedback may have played an important role in star formation quenching. For the massive galaxies at 2 < z < 2.5, both red and green galaxies are found to have a similarly higher AGN fraction than the blue ones, which implies that AGN feedback may help to keep quiescence of red galaxies at z > 2. A significant environmental difference is found between green and red galaxies at z < 1.5. Green and blue galaxies at z > 0.5 seem to have similar local density distributions, suggesting that environment quenching is not the major mechanism to cease star formation at z > 0.5. The fractions of three populations as functions of mass support a “downsizing” quenching picture that the bulk of star formation in more massive galaxies is completed earlier than that of lower-mass galaxies.

Multidimensional neutrino-transport simulations of the core-collapse supernova central engine

NASA Astrophysics Data System (ADS)

O'Connor, Evan; Couch, Sean

2017-01-01

Core-collapse supernovae (CCSNe) mark the explosive death of a massive star. The explosion itself is triggered by the collapse of the iron core that forms near the end of a massive star's life. The core collapses to nuclear densities where the stiff nuclear equation of state halts the collapse and leads to the formation of the supernova shock. In many cases, this shock will eventually propagate throughout the entire star and produces a bright optical display. However, the path from shock formation to explosion has proven difficult to recreate in simulations. Soon after the shock forms, its outward propagation is stagnated and must be revived in order for the CCSNe to be successful. The leading theory for the mechanism that reenergizes the shock is the deposition of energy by neutrinos. In 1D simulations this mechanism fails. However, there is growing evidence that in 2D and 3D, hydrodynamic instabilities can assist the neutrino heating in reviving the shock. In this talk, I will present new multi-D neutrino-radiation-hydrodynamic simulations of CCSNe performed with the FLASH hydrodynamics package. I will discuss the efficacy of neutrino heating in our simulations and show the impact of the multi-D hydrodynamic instabilities.

Massive-Star Magnetospheres: Now in 3-D!

NASA Astrophysics Data System (ADS)

Townsend, Richard

Magnetic fields are unexpected in massive stars, due to the absence of a dynamo convection zone beneath their surface layers. Nevertheless, kilogauss-strength, ordered fields were detected in a small subset of these stars over three decades ago, and the intervening years have witnessed the steady expansion of this subset. A distinctive feature of magnetic massive stars is that they harbor magnetospheres --- circumstellar environments where the magnetic field interacts strongly with the star's radiation-driven wind, confining it and channelling it into energetic shocks. A wide range of observational signatures are associated with these magnetospheres, in diagnostics ranging from X-rays all the way through to radio emission. Moreover, these magnetospheres can play an important role in massive-star evolution, by amplifying angular momentum loss in the wind. Recent progress in understanding massive-star magnetospheres has largely been driven by magnetohydrodynamical (MHD) simulations. However, these have been restricted to two- dimensional axisymmetric configurations, with three-dimensional configurations possible only in certain special cases. These restrictions are limiting further progress; we therefore propose to develop completely general three-dimensional models for the magnetospheres of massive stars, on the one hand to understand their observational properties and exploit them as plasma-physics laboratories, and on the other to gain a comprehensive understanding of how they influence the evolution of their host star. For weak- and intermediate-field stars, the models will be based on 3-D MHD simulations using a modified version of the ZEUS-MP code. For strong-field stars, we will extend our existing Rigid Field Hydrodynamics (RFHD) code to handle completely arbitrary field topologies. To explore a putative 'photoionization-moderated mass loss' mechanism for massive-star magnetospheres, we will also further develop a photoionization code we have recently prototyped. Simulation data from these codes will be used to synthesize observables, suitable for comparison with datasets from ground- and space-based facilities. Project results will be disseminated in the form of journal papers, presentations, data and visualizations, to facilitate the broad communication of our results. In addition, we will release the project codes under an open- source license, to encourage other groups' involvement in modeling massive-star magnetospheres. Through furthering our insights into these magnetospheres, the project is congruous with NASA's Strategic Goal 2, 'Expand scientific understanding of the Earth and the universe in which we live'. By making testable predictions of X-ray emission and UV line profiles, it is naturally synergistic with observational studies of magnetic massive stars using NASA's ROSAT, Chandra, IUE and FUSE missions. By exploring magnetic braking, it will have a direct impact on theoretical predictions of collapsar yields, and thereby help drive forward the analysis and interpretation of gamma-ray burst observations by NASA's Swift and Fermi missions. And, through its general contribution toward understanding the lifecycle of massive stars, the project will complement the past, present and future investments in studying these stars using NASA's other space-based observatories.

A CityGML Extension for Handling Very Large Tins

NASA Astrophysics Data System (ADS)

Kumar, K.; Ledoux, H.; Stoter, J.

2016-10-01

In addition to buildings, the terrain forms an important part of a 3D city model. Although in GIS terrains are usually represented with 2D grids, TINs are also increasingly being used in practice. One example is 3DTOP10NL, the 3D city model covering the whole of the Netherlands, which stores the relief with a constrained TIN containing more than 1 billion triangles. Due to the massive size of such datasets, the main problem that arises is: how to efficiently store and maintain them? While CityGML supports the storage of TINs, we argue in this paper that the current solution is not adequate. For instance, the 1 billion+ triangles of 3DTOP10NL require 686 GB of storage space with CityGML. Furthermore, the current solution does not store the topological relationships of the triangles, and also there are no clear mechanisms to handle several LODs. We propose in this paper a CityGML extension for the compact representation of terrains. We describe our abstract and implementation specifications (modelled in UML), and our prototype implementation to convert TINs to our CityGML structure. It increases the topological relationships that are explicitly represented, and allows us to compress up to a factor of ∼ 25 in our experiments with massive real-world terrains (more than 1 billion triangles).

On Quadratic Divergences in Supergravity, Vacuum Energy and theSupersymmetric Flavor Problem

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gaillard, Mary K.; Nelson, Brent D.

2005-11-18

We examine the phenomenological consequences ofquadratically divergent contributions to the scalar potential insupergravity effective Lagrangians. We focus specifically on the effectof these corrections on the vacuum configurationof scalar fields insoftly-broken supersymmetric theory is and the role these correctionsplay in generating non-diagonal soft scalar masses. Both effects can onlybe properly studied when the divergences are regulated in a manifestlysupersymmetric manner -- something which has ths far been neglected inpast treatments. We show how a supersymmetric regularization can impactpast conclusions about both types of phenomena and discuss what types ofhigh-energy theories are likely to be safe from unwanted flavor-changingneutral current interactions inmore » the context of supergravity theoriesderived from heterotic string compactifications.« less

Classical and quantum analysis of repulsive singularities in four-dimensional extended supergravity

NASA Astrophysics Data System (ADS)

Gaida, I.; Hollmann, H. R.; Stewart, J. M.

1999-07-01

Non-minimal repulsive singularities (`repulsons') in extended supergravity theories are investigated. The short-distance antigravity properties of the repulsons are tested at the classical and the quantum level by a scalar test-particle. Using a partial wave expansion it is shown that the particle is totally reflected at the origin. A high-frequency incoming particle undergoes a phase shift of icons/Journals/Common/pi" ALT="pi" ALIGN="TOP"/>/2. However, the phase shift for a low-frequency particle depends upon the physical data of the repulson. The curvature singularity at a finite distance rh turns out to be transparent for the scalar test-particle and the coordinate singularity at the origin serves as the repulsive barrier to bounce back the particles.

No-scale inflation

NASA Astrophysics Data System (ADS)

Ellis, John; Garcia, Marcos A. G.; Nanopoulos, Dimitri V.; Olive, Keith A.

2016-05-01

Supersymmetry is the most natural framework for physics above the TeV scale, and the corresponding framework for early-Universe cosmology, including inflation, is supergravity. No-scale supergravity emerges from generic string compactifications and yields a non-negative potential, and is therefore a plausible framework for constructing models of inflation. No-scale inflation yields naturally predictions similar to those of the Starobinsky model based on R+{R}2 gravity, with a tilted spectrum of scalar perturbations: {n}s∼ 0.96, and small values of the tensor-to-scalar perturbation ratio r\\lt 0.1, as favoured by Planck and other data on the cosmic microwave background (CMB). Detailed measurements of the CMB may provide insights into the embedding of inflation within string theory as well as its links to collider physics.

The effective supergravity of little string theory

NASA Astrophysics Data System (ADS)

Antoniadis, Ignatios; Delgado, Antonio; Markou, Chrysoula; Pokorski, Stefan

2018-02-01

In this work we present the minimal supersymmetric extension of the five-dimensional dilaton-gravity theory that captures the main properties of the holographic dual of little string theory. It is described by a particular gauging of N=2 supergravity coupled with one vector multiplet associated with the string dilaton, along the U(1) subgroup of SU(2) R-symmetry. The linear dilaton in the fifth coordinate solution of the equations of motion (with flat string frame metric) breaks half of the supersymmetries to N=1 in four dimensions. Interest in the linear dilaton model has lately been revived in the context of the clockwork mechanism, which has recently been proposed as a new source of exponential scale separation in field theory.

Identification of dusty massive stars in star-forming dwarf irregular galaxies in the Local Group with mid-IR photometry

NASA Astrophysics Data System (ADS)

Britavskiy, N. E.; Bonanos, A. Z.; Mehner, A.; Boyer, M. L.; McQuinn, K. B. W.

2015-12-01

Context. Increasing the statistics of spectroscopically confirmed evolved massive stars in the Local Group enables the investigation of the mass loss phenomena that occur in these stars in the late stages of their evolution. Aims: We aim to complete the census of luminous mid-IR sources in star-forming dwarf irregular (dIrr) galaxies of the Local Group. To achieve this we employed mid-IR photometric selection criteria to identify evolved massive stars, such as red supergiants (RSGs) and luminous blue variables (LBVs), by using the fact that these types of stars have infrared excess due to dust. Methods: The method is based on 3.6 μm and 4.5 μm photometry from archival Spitzer Space Telescope images of nearby galaxies. We applied our criteria to four dIrr galaxies: Pegasus, Phoenix, Sextans A, and WLM, selecting 79 point sources that we observed with the VLT/FORS2 spectrograph in multi-object spectroscopy mode. Results: We identified 13 RSGs, of which 6 are new discoveries, as well as two new emission line stars, and one candidate yellow supergiant. Among the other observed objects we identified carbon stars, foreground giants, and background objects, such as a quasar and an early-type galaxy that contaminate our survey. We use the results of our spectroscopic survey to revise the mid-IR and optical selection criteria for identifying RSGs from photometric measurements. The optical selection criteria are more efficient in separating extragalactic RSGs from foreground giants than mid-IR selection criteria, but the mid-IR selection criteria are useful for identifying dusty stars in the Local Group. This work serves as a basis for further investigation of the newly discovered dusty massive stars and their host galaxies. Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme IDs 090.D-0009 and 091.D-0010.Appendix A is available in electronic form at http://www.aanda.org

A novel adaptive algorithm for 3D finite element analysis to model extracortical bone growth.

PubMed

Cheong, Vee San; Blunn, Gordon W; Coathup, Melanie J; Fromme, Paul

2018-02-01

Extracortical bone growth with osseointegration of bone onto the shaft of massive bone tumour implants is an important clinical outcome for long-term implant survival. A new computational algorithm combining geometrical shape changes and bone adaptation in 3D Finite Element simulations has been developed, using a soft tissue envelope mesh, a novel concept of osteoconnectivity, and bone remodelling theory. The effects of varying the initial tissue density, spatial influence function and time step were investigated. The methodology demonstrated good correspondence to radiological results for a segmental prosthesis.

Trisomy 13 and Massive Fetomaternal Hemorrhage

PubMed Central

Matsui, Ryoko; Suzuki, Shunji; Ito, Marie; Terada, Yusuke; Kumasaka, Sakae

2015-01-01

This is the first case report of trisomy 13 complicated by massive fetomaternal hemorrhage (FMH). A pale male infant weighing 2,950 g was delivered with low Apgar scores by emergency cesarean section due to non-reassuring fetal status. The umbilical arterial pH and hemoglobin level were 6.815 and 6.9 g/dL (normal: 13 - 22 g/dL), respectively. The maternal hemoglobin-F and serum alpha-fetoprotein levels were 6.0% (normal: < 1.0%) and 1,150 ng/mL (4.1 multiple of median), respectively. The neonate was diagnosed as having trisomy 13 by a subsequent chromosome examination. In the placenta, massive intervillous thrombosis was observed microscopically. This placental finding has been reported to be associated with both preeclampsia and massive FMH. In addition, the incidence of preeclampsia in pregnancies complicated by trisomy 13 has been reported to be significantly higher than normal karyotype populations. Therefore, the current finding may support the association between trisomy 13 and the incidence of massive FMH. PMID:26015824

Applications of warped geometries: From cosmology to cold atoms

NASA Astrophysics Data System (ADS)

Brown, C. M.

This thesis describes several interrelated projects furthering the study of branes on warped geometries in string theory. First, we consider the non-perturbative interaction between D3 and D7 branes which stabilizes the overall volume in braneworld compactification scenarios. This interaction might offer stable nonsupersymmetric vacua which would naturally break supersymmetry if occupied by D3 branes. We derive the equations for the nonsupersymmetric vacua of the D3-brane and analyze them in the case of two particular 7-brane embeddings at the bottom of the warped deformed conifold. These geometries have negative dark energy. Stability of these models is possible but not generic. Further, we reevaluate brane/flux annihilation in a warped throat with one stabilized Kahler modulus. We find that depending on the relative size of various fluxes three things can occur: the decay process proceeds unhindered, the D3-branes are forbidden to decay classically, or the entire space decompactifies. Additionally, we show that the Kahler modulus receives a contribution from the collective 3-brane tension allowing significant changes in the compactified volume during the transition. Next, furthering the effort to describe cold atoms using AdS/CFT, we construct charged asymptotically Schrodinger black hole solutions of IIB supergravity. We begin by obtaining a closed-form expression for the null Melvin twist of many type IIB backgrounds and identify the resulting five-dimensional effective action. We use these results to demonstrate that the near-horizon physics and thermodynamics of asymptotically Schrodinger black holes obtained in this way are essentially inherited from their AdS progenitors, and verify that they admit zero-temperature extremal limits with AdS2 near-horizon geometries. Finally, in an effort to understand rotating nonrelativistic systems we use the null Melvin twist technology on a charged rotating AdS black hole and discover a type of Godel space-time. We discuss how the dual field theory avoids the closed time-like curves which arise because of Bousso's holographic screen conjecture. This Godel space-time is locally equivalent to a Schrodinger space-time that has been forced onto an S2.

3D Hydrodynamic & Radiative Transfer Models of HETG Line Profiles from Colliding Winds

NASA Astrophysics Data System (ADS)

Russell, Christopher

2016-09-01

Chandra has invested 2.52 Ms of HETG observations into 4 colliding-wind binary (CWB) systems. WR140 and eta Car are massive-star binaries with long periods that produce X-rays in a 3D, warped shock cone, while delta Ori A and HD150136 are short-period systems that show line profile changes due to embedded-wind-shock emission in the primary wind being partially evacuated by the secondary wind. HETG observations resolve the velocity structure in both types of systems. We propose 3D line-profile radiative-transfer calculations on existing 3D hydrodynamic simulations of these 4 CWBs. This is the first confrontation of these data with this level of modeling, and will provide greater understanding of their stellar, wind, and orbital properties, as well as the underlying CWB shock physics.

Differential cross sections of D*+/- photoproduction in ep collisions at HERA

NASA Astrophysics Data System (ADS)

Breitweg, J.; Derrick, M.; Krakauer, D.; Magill, S.; Mikunas, D.; Musgrave, B.; Repond, J.; Stanek, R.; Talaga, R. L.; Yoshida, R.; Zhang, H.; Mattingly, M. C. K.; Anselmo, F.; Antonioli, P.; Bari, G.; Basile, M.; Bellagamba, L.; Boscherini, D.; Bruni, A.; Bruni, G.; Romeo, G. Cara; Castellini, G.; Cifarelli, L.; Cindolo, F.; Contin, A.; Corradi, M.; Gialas, I.; Giusti, P.; Iacobucci, G.; Laurenti, G.; Levi, G.; Margotti, A.; Massam, T.; Nania, R.; Palmonari, F.; de Pasquale, S.; Pesci, A.; Polini, A.; Sartorelli, G.; Garcia, Y. Zamora; Zichichi, A.; Amelung, C.; Bornheim, A.; Brock, I.; Coböken, K.; Crittenden, J.; Deffner, R.; Eckert, M.; Feld, L.; Grothe, M.; Hartmann, H.; Heinloth, K.; Heinz, L.; Hilger, E.; Jakob, H.-P.; Katz, U. F.; Paul, E.; Pfeiffer, M.; Rembser, Ch.; Stamm, J.; Wedemeyer, R.; Bailey, D. S.; Campbell-Robson, S.; Cottingham, W. N.; Foster, B.; Hall-Wilton, R.; Hayes, M. E.; Heath, G. P.; Heath, H. F.; Piccioni, D.; Roff, D. G.; Tapper, R. J.; Arneodo, M.; Ayad, R.; Capua, M.; Garfagnini, A.; Iannotti, L.; Schioppa, M.; Susinno, G.; Kim, J. Y.; Lee, J. H.; Lim, I. T.; Pac, M. Y.; Caldwell, A.; Cartiglia, N.; Jing, Z.; Liu, W.; Parsons, J. A.; Ritz, S.; Sampson, S.; Sciulli, F.; Straub, P. B.; Zhu, Q.; Borzemski, P.; Chwastowski, J.; Eskreys, A.; Jakubowski, Z.; Przybycień, M. B.; Zachara, M.; Zawiejski, L.; Adamczyk, L.; Bednarek, B.; Jeleń, K.; Kisielewska, D.; Kowalski, T.; Przybycień, M.; Rulikowska-Zarȩbska, E.; Suszycki, L.; Zajac, J.; Duliński, Z.; Kotański, A.; Kotański, A.; Abbiendi, G.; Abramowicz, H.; Bauerdick, L. A. T.; Behrens, U.; Beier, H.; Bienlein, J. K.; Cases, G.; Deppe, O.; Desler, K.; Drews, G.; Gilkinson, D. J.; Glasman, C.; Göttlicher, P.; Große-Knetter, J.; Haas, T.; Hain, W.; Hasell, D.; Heßling, H.; Iga, Y.; Johnson, K. F.; Kasemann, M.; Koch, W.; Kötz, U.; Kowalski, H.; Labs, J.; Lindemann, L.; Löhr, B.; Löwe, M.; Mainusch, J.; Mańczak, O.; Milewski, J.; Monteiro, T.; Ng, J. S. T.; Notz, D.; Ohrenberg, K.; Park, I. H.; Pellegrino, A.; Pelucchi, F.; Piotrzkowski, K.; Roco, M.; Rohde, M.; Roldán, J.; Savin, A. A.; Schneekloth, U.; Schulz, W.; Selonke, F.; Surrow, B.; Tassi, E.; Voß, T.; Westphal, D.; Wolf, G.; Wollmer, U.; Youngman, C.; Żarnecki, A. F.; Zeuner, W.; Burow, B. D.; Grabosch, H. J.; Meyer, A.; Schlenstedt, S.; Barbagli, G.; Gallo, E.; Pelfer, P.; Maccarrone, G.; Votano, L.; Bamberger, A.; Eisenhardt, S.; Markun, P.; Trefzger, T.; Wölfle, S.; Bromley, J. T.; Brook, N. H.; Bussey, P. J.; Doyle, A. T.; Saxon, D. H.; Sinclair, L. E.; Strickland, E.; Utley, M. L.; Waugh, R.; Wilson, A. S.; Bohnet, I.; Gendner, N.; Holm, U.; Meyer-Larsen, A.; Salehi, H.; Wick, K.; Gladilin, L. K.; Klanner, R.; Lohrmann, E.; Poelz, G.; Schott, W.; Zetsche, F.; Bacon, T. C.; Butterworth, I.; Cole, J. E.; Harris, V. L.; Howell, G.; Hung, B. H. Y.; Lamberti, L.; Long, K. R.; Miller, D. B.; Pavel, N.; Prinias, A.; Sedgbeer, J. K.; Sideris, D.; Whitfield, A. F.; Mallik, U.; Wang, S. M.; Wu, J. T.; Cloth, P.; Filges, D.; An, S. H.; Lee, S. B.; Nam, S. W.; Park, H. S.; Park, S. K.; Barreiro, F.; Fernandez, J. P.; Graciani, R.; Hernández, J. M.; Hervás, L.; Labarga, L.; Martinez, M.; del Peso, J.; Puga, J.; Terron, J.; de Trocóniz, J. F.; Corriveau, F.; Hanna, D. S.; Hartmann, J.; Hung, L. W.; Lim, J. N.; Murray, W. N.; Ochs, A.; Riveline, M.; Stairs, D. G.; St-Laurent, M.; Ullmann, R.; Tsurugai, T.; Bashkirov, V.; Dolgoshein, B. A.; Stifutkin, A.; Bashindzhagyan, G. L.; Ermolov, P. F.; Golubkov, Yu. A.; Kobrin, V. D.; Korzhavina, I. A.; Kuzmin, V. A.; Lukina, O. Yu.; Proskuryakov, A. S.; Shcheglova, L. M.; Solomin, A. N.; Zotov, N. P.; Bokel, C.; Botje, M.; Brümmer, N.; Chlebana, F.; Engelen, J.; de Kamps, M.; Kooijman, P.; Kruse, A.; van Sighem, A.; Tiecke, H.; Verkerke, W.; Vossebeld, J.; Vreeswijk, M.; Wiggers, L.; de Wolf, E.; Acosta, D.; Bylsma, B.; Durkin, L. S.; Gilmore, J.; Ginsburg, C. M.; Kim, C. L.; Ling, T. Y.; Nylander, P.; Romanowski, T. A.; Blaikley, H. E.; Cashmore, R. J.; Cooper-Sarkar, A. M.; Devenish, R. C. E.; Edmonds, J. K.; Harnew, N.; Lancaster, M.; McFall, J. D.; Nath, C.; Noyes, V. A.; Quadt, A.; Tickner, J. R.; Uijterwaal, H.; Walczak, R.; Waters, D. S.; Yip, T.; Bertolin, A.; Brugnera, R.; Carlin, R.; dal Corso, F.; Dosselli, U.; Limentani, S.; Morandin, M.; Posocco, M.; Stanco, L.; Stroili, R.; Voci, C.; Bulmahn, J.; Feild, R. G.; Oh, B. Y.; Okrasiński, J. R.; Whitmore, J. J.; D'Agostini, G.; Marini, G.; Nigro, A.; Hart, J. C.; McCubbin, N. A.; Shah, T. P.; Barberis, E.; Dubbs, T.; Heusch, C.; van Hook, M.; Lockman, W.; Rahn, J. T.; Sadrozinski, H. F.-W.; Seiden, A.; Williams, D. C.; Schwarzer, O.; Walenta, A. H.; Briskin, G.; Dagan, S.; Doeker, T.; Levy, A.; Abe, T.; Fleck, J. I.; Inuzuka, M.; Ishii, T.; Kuze, M.; Nagano, K.; Nakao, M.; Suzuki, I.; Tokushuku, K.; Umemori, K.; Yamada, S.; Yamazaki, Y.; Hamatsu, R.; Hirose, T.; Homma, K.; Kitamura, S.; Matsushita, T.; Yamauchi, K.; Cirio, R.; Costa, M.; Ferrero, M. I.; Maselli, S.; Monaco, V.; Peroni, C.; Petrucci, M. C.; Sacchi, R.; Solano, A.; Staiano, A.; Dardo, M.; Bailey, D. C.; Brkic, M.; Fagerstroem, C.-P.; Hartner, G. F.; Joo, K. K.; Levman, G. M.; Martin, J. F.; Orr, R. S.; Polenz, S.; Sampson, C. R.; Simmons, D.; Teuscher, R. J.; Butterworth, J. M.; Catterall, C. D.; Jones, T. W.; Kaziewicz, P. B.; Lane, J. B.; Saunders, R. L.; Shulman, J.; Sutton, M. R.; Lu, B.; Mo, L. W.; Ciborowski, J.; Grzelak, G.; Kasprzak, M.; Muchorowski, K.; Nowak, R. J.; Pawlak, J. M.; Pawlak, R.; Tymieniecka, T.; Wróblewski, A. K.; Zakrzewski, J. A.; Adamus, M.; Coldewey, C.; Eisenberg, Y.; Hochman, D.; Karshon, U.; Revel, D.; Zer-Zion, D.; Badgett, W. F.; Chapin, D.; Cross, R.; Dasu, S.; Foudas, C.; Loveless, R. J.; Mattingly, S.; Reeder, D. D.; Smith, W. H.; Vaiciulis, A.; Wodarczyk, M.; Bhadra, S.; Frisken, W. R.; Khakzad, M.; Schmidke, W. B.

1997-02-01

Inclusive photoproduction of D*+/- in ep collisions at HERA has been measured with the ZEUS detector for photon-proton centre of mass energies in the range 115 < W < 280 GeV and photon virtuality Q2 < 4 GeV2. The cross section σep -> D* X integrated over the kinematic region pD*⊥ > 3 GeV and -1.5 < ηD* < 1.0 is (10.6 +/- 1.7 (stat.) +/-1.61.3 (syst.)) nb. Differential cross sections as functions of pD*⊥, ηD* and W are given. The data are compared with two next-to-leading order perturbative QCD predictions. For a calculation using a massive charm scheme the predicted cross sections are smaller than the measured ones. A recent calculation using a massless charm scheme is in agreement with the data.

Progressive 3D shape abstraction via hierarchical CSG tree

NASA Astrophysics Data System (ADS)

Chen, Xingyou; Tang, Jin; Li, Chenglong

2017-06-01

A constructive solid geometry(CSG) tree model is proposed to progressively abstract 3D geometric shape of general object from 2D image. Unlike conventional ones, our method applies to general object without the need for massive CAD models, and represents the object shapes in a coarse-to-fine manner that allows users to view temporal shape representations at any time. It stands in a transitional position between 2D image feature and CAD model, benefits from state-of-the-art object detection approaches and better initializes CAD model for finer fitting, estimates 3D shape and pose parameters of object at different levels according to visual perception objective, in a coarse-to-fine manner. Two main contributions are the application of CSG building up procedure into visual perception, and the ability of extending object estimation result into a more flexible and expressive model than 2D/3D primitive shapes. Experimental results demonstrate the feasibility and effectiveness of the proposed approach.

Spontaneous Breaking of Scale Invariance in U(N) Chern-Simons Gauge Theories in Three Dimensions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bardeen, William A.

2015-09-24

I explore the existence of a massive phase in a conformally invariant U(N) Chern-Simons gauge theories in D = 3 with matter fields in the fundamental representation. These models have attracted recent attention as being dual, in the conformal phase, to theories of higher spin gravity on AdS 4. Using the 0t Hooft large N expansion, exact solutions are obtained for scalar current correlators in the massive phase where the conformal symmetry is spontaneously broken. A massless dilaton appears as a composite state, and its properties are discussed. Solutions exist for matters field that are either bosons or fermions.

Spontaneous Breaking of Scale Invariance in U(N) Chern-Simons Gauge Theories in Three Dimensions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bardeen, William

2014-10-24

I explore the existence of a massive phase in a conformally invariant U(N) Chern-Simons gauge theories in D = 3 with matter fields in the fundamental representation. These models have attracted recent attention as being dual, in the conformal phase, to theories of higher spin gravity on AdS 4. Using the 1t Hooft large N expansion, exact solutions are obtained for scalar current correlators in the massive phase where the conformal symmetry is spontaneously broken. A massless dilaton appears as a composite state, and its properties are discussed. Solutions exist for matters field that are either bosons or fermions.

Smart integrated microsystems: the energy efficiency challenge (Conference Presentation) (Plenary Presentation)

NASA Astrophysics Data System (ADS)

Benini, Luca

2017-06-01

The "internet of everything" envisions trillions of connected objects loaded with high-bandwidth sensors requiring massive amounts of local signal processing, fusion, pattern extraction and classification. From the computational viewpoint, the challenge is formidable and can be addressed only by pushing computing fabrics toward massive parallelism and brain-like energy efficiency levels. CMOS technology can still take us a long way toward this goal, but technology scaling is losing steam. Energy efficiency improvement will increasingly hinge on architecture, circuits, design techniques such as heterogeneous 3D integration, mixed-signal preprocessing, event-based approximate computing and non-Von-Neumann architectures for scalable acceleration.

A Spatially-Registered, Massively Parallelised Data Structure for Interacting with Large, Integrated Geodatasets

NASA Astrophysics Data System (ADS)

Irving, D. H.; Rasheed, M.; O'Doherty, N.

2010-12-01

The efficient storage, retrieval and interactive use of subsurface data present great challenges in geodata management. Data volumes are typically massive, complex and poorly indexed with inadequate metadata. Derived geomodels and interpretations are often tightly bound in application-centric and proprietary formats; open standards for long-term stewardship are poorly developed. Consequently current data storage is a combination of: complex Logical Data Models (LDMs) based on file storage formats; 2D GIS tree-based indexing of spatial data; and translations of serialised memory-based storage techniques into disk-based storage. Whilst adequate for working at the mesoscale over a short timeframes, these approaches all possess technical and operational shortcomings: data model complexity; anisotropy of access; scalability to large and complex datasets; and weak implementation and integration of metadata. High performance hardware such as parallelised storage and Relational Database Management System (RDBMS) have long been exploited in many solutions but the underlying data structure must provide commensurate efficiencies to allow multi-user, multi-application and near-realtime data interaction. We present an open Spatially-Registered Data Structure (SRDS) built on Massively Parallel Processing (MPP) database architecture implemented by a ANSI SQL 2008 compliant RDBMS. We propose a LDM comprising a 3D Earth model that is decomposed such that each increasing Level of Detail (LoD) is achieved by recursively halving the bin size until it is less than the error in each spatial dimension for that data point. The value of an attribute at that point is stored as a property of that point and at that LoD. It is key to the numerical efficiency of the SRDS that it is under-pinned by a power-of-two relationship thus precluding the need for computationally intensive floating point arithmetic. Our approach employed a tightly clustered MPP array with small clusters of storage, processors and memory communicating over a high-speed network inter-connect. This is a shared-nothing architecture where resources are managed within each cluster unlike most other RDBMSs. Data are accessed on this architecture by their primary index values which utilises the hashing algorithm for point-to-point access. The hashing algorithm’s main role is the efficient distribution of data across the clusters based on the primary index. In this study we used 3D seismic volumes, 2D seismic profiles and borehole logs to demonstrate application in both (x,y,TWT) and (x,y,z)-space. In the SRDS the primary index is a composite column index of (x,y) to avoid invoking time-consuming full table scans as is the case in tree-based systems. This means that data access is isotropic. A query for data in a specified spatial range permits retrieval recursively by point-to-point queries within each nested LoD yielding true linear performance up to the Petabyte scale with hardware scaling presenting the primary limiting factor. Our architecture and LDM promotes: realtime interaction with massive data volumes; streaming of result sets and server-rendered 2D/3D imagery; rigorous workflow control and auditing; and in-database algorithms run directly against data as a HPC cloud service.

3D hydrodynamic simulations of carbon burning in massive stars

NASA Astrophysics Data System (ADS)

Cristini, A.; Meakin, C.; Hirschi, R.; Arnett, D.; Georgy, C.; Viallet, M.; Walkington, I.

2017-10-01

We present the first detailed 3D hydrodynamic implicit large eddy simulations of turbulent convection of carbon burning in massive stars. Simulations begin with radial profiles mapped from a carbon-burning shell within a 15 M⊙ 1D stellar evolution model. We consider models with 1283, 2563, 5123, and 10243 zones. The turbulent flow properties of these carbon-burning simulations are very similar to the oxygen-burning case. We performed a mean field analysis of the kinetic energy budgets within the Reynolds-averaged Navier-Stokes framework. For the upper convective boundary region, we find that the numerical dissipation is insensitive to resolution for linear mesh resolutions above 512 grid points. For the stiffer, more stratified lower boundary, our highest resolution model still shows signs of decreasing sub-grid dissipation suggesting it is not yet numerically converged. We find that the widths of the upper and lower boundaries are roughly 30 per cent and 10 per cent of the local pressure scaleheights, respectively. The shape of the boundaries is significantly different from those used in stellar evolution models. As in past oxygen-shell-burning simulations, we observe entrainment at both boundaries in our carbon-shell-burning simulations. In the large Péclet number regime found in the advanced phases, the entrainment rate is roughly inversely proportional to the bulk Richardson number, RiB (∝RiB-α, 0.5 ≲ α ≲ 1.0). We thus suggest the use of RiB as a means to take into account the results of 3D hydrodynamics simulations in new 1D prescriptions of convective boundary mixing.

3-Dimesional Structure of Factor D

NASA Technical Reports Server (NTRS)

2004-01-01

The trauma caused by the open heart surgery often triggers massive inflammation because the immune system overreacts. Factor D, the protein which plays a key role in the biological steps that activate this immune response prevents the imune system from inappropriately rurning out of control, allowing the patient to recover more rapidly. Factor D blockers, with their great potential to alleviate the complication of inflammation associated with heart surgery, are now being developed for clinical trials. These new drugs, developed from space research, should be commercially available as soon as year 2001.

Supergravity separation of Pb and Sn from waste printed circuit boards at different temperatures

NASA Astrophysics Data System (ADS)

Meng, Long; Wang, Zhe; Zhong, Yi-wei; Chen, Kui-yuan; Guo, Zhan-cheng

2018-02-01

Printed circuit boards (PCBs) contain many toxic substances as well as valuable metals, e.g., lead (Pb) and tin (Sn). In this study, a novel technology, named supergravity, was used to separate different mass ratios of Pb and Sn from Pb-Sn alloys in PCBs. In a supergravity field, the liquid metal phase can permeate from solid particles. Hence, temperatures of 200, 280, and 400°C were chosen to separate Pb and Sn from PCBs. The results depicted that gravity coefficient only affected the recovery rates of Pb and Sn, whereas it had little effect on the mass ratios of Pb and Sn in the obtained alloys. With an increase in gravity coefficient, the recovery values of Pb and Sn in each step of the separation process increased. In the single-step separation process, the mass ratios of Pb and Sn in Pb-Sn alloys were 0.55, 0.40, and 0.64 at 200, 280, and 400°C, respectively. In the two-step separation process, the mass ratios were 0.12 and 0.55 at 280 and 400°C, respectively. Further, the mass ratio was observed to be 0.76 at 400°C in the three-step separation process. This process provides an innovative approach to the recycling mechanism of Pb and Sn from PCBs.

The MASSIVE Survey. VI. The Spatial Distribution and Kinematics of Warm Ionized Gas in the Most Massive Local Early-type Galaxies

NASA Astrophysics Data System (ADS)

Pandya, Viraj; Greene, Jenny E.; Ma, Chung-Pei; Veale, Melanie; Ene, Irina; Davis, Timothy A.; Blakeslee, John P.; Goulding, Andy D.; McConnell, Nicholas J.; Nyland, Kristina; Thomas, Jens

2017-03-01

We present the first systematic investigation of the existence, spatial distribution, and kinematics of warm ionized gas as traced by the [O II] 3727 Å emission line in 74 of the most massive galaxies in the local universe. All of our galaxies have deep integral-field spectroscopy from the volume- and magnitude-limited MASSIVE survey of early-type galaxies with stellar mass {log}({M}* /{M}⊙ )> 11.5 (M K < -25.3 mag) and distance D < 108 Mpc. Of the 74 galaxies in our sample, we detect warm ionized gas in 28, which yields a global detection fraction of 38 ± 6% down to a typical [O II] equivalent width limit of 2 Å. MASSIVE fast rotators are more likely to have gas than MASSIVE slow rotators with detection fractions of 80 ± 10% and 28 ± 6%, respectively. The spatial extents span a wide range of radii (0.6-18.2 kpc; 0.1-4R e ), and the gas morphologies are diverse, with 17/28 ≈ 61 ± 9% being centrally concentrated, 8/28 ≈ 29 ± 9% exhibiting clear rotation out to several kiloparsecs, and 3/28 ≈ 11 ± 6% being extended but patchy. Three out of four fast rotators show kinematic alignment between the stars and gas, whereas the two slow rotators with robust kinematic measurements available exhibit kinematic misalignment. Our inferred warm ionized gas masses are roughly ˜105 M ⊙. The emission line ratios and radial equivalent width profiles are generally consistent with excitation of the gas by the old underlying stellar population. We explore different gas origin scenarios for MASSIVE galaxies and find that a variety of physical processes are likely at play, including internal gas recycling, cooling out of the hot gaseous halo, and gas acquired via mergers.

Dynamical Models for High-Energy Emission from Massive Stars

NASA Astrophysics Data System (ADS)

Owocki, Stanley %FAA(University of Delaware)

Massive stars are prominent sources of X-rays and gamma-rays detected by both targeted and survey observations from orbiting telescopes like Chandra, XMM/Newton, RXTE, and Fermi. Such high-energy emissions represent key probes of the dynamics of massive-star mass loss, and their penetration through many magnitudes of visible interstellar extinction makes them effective beacons of massive stars in distant reaches of the Galaxy, and in young, active star-forming regions. The project proposed here will develop a comprehensive theoretical framework for interpreting both surveys and targeted observations of high-energy emission from massive stars. It will build on our team's extensive experience in both theoretical models and observational analyses for three key types of emission mechanisms in the stellar wind outflows of these stars, namely: 1) Embedded Wind Shocks (EWS) arising from internal instabilities in the wind driving; 2) shocks in Colliding Wind Binary (CWB) systems; and 3) High-Mass X-ray Binaries (HMXB) systems with interaction between massive-star wind with a compact companion (neutron star or black hole). Taking advantage of commonalities in the treatment of radiative driving, hydrodynamics, shock heating and cooling, and radiation transport, we will develop radiation hydrodynamical models for the key observational signatures like energy distribution, emission line spectrum, and variability, with an emphasis on how these can be used in affiliated analyses of both surveys like the recent Chandra mapping of the Carina association, and targeted observations of galactic X-ray and gamma-ray sources associated with each of the above specific model types. The promises of new clumping-insensitive diagnostics of mass loss rates, and the connection to mass transfer and binarity, all have broad relevance for understanding the origin, evolution, and fate of massive stars, in concert with elements of NASA's Strategic Subgoal 3D. Building on our team's expertise, the project emphasizes training of a new generation of students and post-doctoral researchers to model and analyze observations by current and future NASA X-ray and gamma-ray observatories.

Studies of contemporary glacier basal ice cryostructures to identify buried basal ice in the permafrost: an example from the Matanuska Glacier, Alaska.

NASA Astrophysics Data System (ADS)

Stephani, E.; Fortier, D.; Kanevskiy, M.; Dillon, M.; Shur, Y.

2007-12-01

In the permafrost, massive ice bodies occur as buried glacier ice, aufeis ice, recrystalized snow, massive segregated ice, injection ice, ice wedges or ice formed in underground cavities ("pool ice", "thermokarst-cave ice"). The origin of massive ice bodies in the permafrost bears considerable implications for the reconstructions of paleoenvironments and paleoclimates. Our work aims to help the permafrost scientists working on massive icy sediments to distinguish buried basal glacier ice from other types of buried ice. To do so, the properties and structure of contemporary basal ice must be well known. Field investigations at the Matanuska Glacier (Chugach range, South-central Alaska), consisted in descriptions and sampling of natural basal ice exposures. We have used the basal ice facies classification of Lawson (1979) which is simple, easy to use in the field and provides a good framework for the description of basal ice exposures. Cores were extracted and brought back to the laboratory for water and grain-size analyses. The sediments forming the cryostructure were mostly polymodal, poorly sorted gravelly silt to gravelly fine sand, with mud contents generally over 50%. These data will be used to calibrate three-dimensional (3D) models produced from micro-tomographic scans of basal ice which will produce quantitative estimates of volumetric ice and sediments contents of basal ice cryostructures. Ultimately, visual qualitative and quantitative characterization of the basal ice components of 3D models together with field observations and laboratory analysis will allow for a new micro-facies and cryostructures classification of the basal ice. Our work will also have applications in glaciology, glacial geology, geomorphology, Quaternary and paleo-climatological studies based on inferences made from the structure of basal glacier ice. This paper presents the internal composition of the basal ice facies in terms of cryostructures assemblages (Fortier et al.: 2007) and sedimentological properties. Fortier, D., Kanevskiy, M, Stephani, E., Dillon, M., Shur, Y. 2007. Facies and cryostructures of glacier basal ice as an object of permafrost study, an example from the Matanuska Glacier, Alaska. Canadian Quaternary Association Conference, Ottawa, June 2007: 75. Lawson, D.E. 1979. Sedimentological analysis of the western terminus region of the Matanuska Glacier, Alaska. Cold Regions Engineering and Research Laboratory, Hanover, N.H., Report 79-9.

Tribrid Inflation in Supergravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Antusch, Stefan; Dutta, Koushik; Kostka, Philipp M.

2010-02-10

We propose a novel class of F-term hybrid inflation models in supergravity (SUGRA) where the eta-problem is resolved using either a Heisenberg symmetry or a shift symmetry of the Kaehler potential. In addition to the inflaton and the waterfall field, this class (referred to as tribrid inflation) contains a third 'driving' field which contributes the large vacuum energy during inflation by its F-term. In contrast to the 'standard' hybrid scenario, it has several attractive features due to the property of vanishing inflationary superpotential (W{sub inf} = 0) during inflation. While the symmetries of the Kaehler potential ensure a flat inflatonmore » potential at tree-level, quantum corrections induced by symmetry breaking terms in the superpotential generate a slope of the potential and lead to a spectral tilt consistent with recent WMAP observations.« less

Fine-tuning with brane-localized flux in 6D supergravity

NASA Astrophysics Data System (ADS)

Niedermann, Florian; Schneider, Robert

2016-02-01

There are claims in the literature that the cosmological constant problem could be solved in a braneworld model with two large (micron-sized) supersymmetric extra dimensions. The mechanism relies on two basic ingredients: first, the cosmological constant only curves the compact bulk geometry into a rugby shape while the 4D curvature stays flat. Second, a brane-localized flux term is introduced in order to circumvent Weinberg's fine-tuning argument, which otherwise enters here through a backdoor via the flux quantization condition. In this paper, we show that the latter mechanism does not work in the way it was designed: the only localized flux coupling that guarantees a flat on-brane geometry is one which preserves the scale invariance of the bulk theory. Consequently, Weinberg's argument applies, making a fine-tuning necessary again. The only remaining window of opportunity lies within scale invariance breaking brane couplings, for which the tuning could be avoided. Whether the corresponding 4D curvature could be kept under control and in agreement with the observed value will be answered in our companion paper [1].

Massively parallel electrical conductivity imaging of the subsurface: Applications to hydrocarbon exploration

NASA Astrophysics Data System (ADS)

Newman, Gregory A.; Commer, Michael

2009-07-01

Three-dimensional (3D) geophysical imaging is now receiving considerable attention for electrical conductivity mapping of potential offshore oil and gas reservoirs. The imaging technology employs controlled source electromagnetic (CSEM) and magnetotelluric (MT) fields and treats geological media exhibiting transverse anisotropy. Moreover when combined with established seismic methods, direct imaging of reservoir fluids is possible. Because of the size of the 3D conductivity imaging problem, strategies are required exploiting computational parallelism and optimal meshing. The algorithm thus developed has been shown to scale to tens of thousands of processors. In one imaging experiment, 32,768 tasks/processors on the IBM Watson Research Blue Gene/L supercomputer were successfully utilized. Over a 24 hour period we were able to image a large scale field data set that previously required over four months of processing time on distributed clusters based on Intel or AMD processors utilizing 1024 tasks on an InfiniBand fabric. Electrical conductivity imaging using massively parallel computational resources produces results that cannot be obtained otherwise and are consistent with timeframes required for practical exploration problems.

Realization of Massive Relativistic Spin- 3 / 2 Rarita-Schwinger Quasiparticle in Condensed Matter Systems

NASA Astrophysics Data System (ADS)

Tang, Feng; Luo, Xi; Du, Yongping; Yu, Yue; Wan, Xiangang

Very recently, there has been significant progress in realizing high-energy particles in condensed matter system (CMS) such as the Dirac, Weyl and Majorana fermions. Besides the spin-1/2 particles, the spin-3/2 elementary particle, known as the Rarita-Schwinger (RS) fermion, has not been observed or simulated in the laboratory. The main obstacle of realizing RS fermion in CMS lies in the nontrivial constraints that eliminate the redundant degrees of freedom in its representation of the Poincaré group. In this Letter, we propose a generic method that automatically contains the constraints in the Hamiltonian and prove the RS modes always exist and can be separated from the other non-RS bands. Through symmetry considerations, we show that the two dimensional (2D) massive RS (M-RS) quasiparticle can emerge in several trigonal and hexagonal lattices. Based on ab initio calculations, we predict that the thin film of CaLiX (X=Ge and Si) may host 2D M-RS excitations near the Fermi level. and Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China.

A full general relativistic neutrino radiation-hydrodynamics simulation of a collapsing very massive star and the formation of a black hole

NASA Astrophysics Data System (ADS)

Kuroda, Takami; Kotake, Kei; Takiwaki, Tomoya; Thielemann, Friedrich-Karl

2018-06-01

We study the final fate of a very massive star by performing full general relativistic (GR), three-dimensional (3D) simulation with three-flavour multi-energy neutrino transport. Utilizing a 70 solar mass zero-metallicity progenitor, we self-consistently follow the radiation-hydrodynamics from the onset of gravitational core-collapse until the second collapse of the proto-neutron star (PNS), leading to black hole (BH) formation. Our results show that the BH formation occurs at a post-bounce time of Tpb ˜ 300 ms for the 70 M⊙ star. This is significantly earlier than those in the literature where lower mass progenitors were employed. At a few ˜10 ms before BH formation, we find that the stalled bounce shock is revived by intense neutrino heating from the very hot PNS, which is aided by violent convection behind the shock. In the context of 3D-GR core-collapse modelling with multi-energy neutrino transport, our numerical results present the first evidence to validate a fallback BH formation scenario of the 70 M⊙ star.

Combined algorithmic and GPU acceleration for ultra-fast circular conebeam backprojection

NASA Astrophysics Data System (ADS)

Brokish, Jeffrey; Sack, Paul; Bresler, Yoram

2010-04-01

In this paper, we describe the first implementation and performance of a fast O(N3logN) hierarchical backprojection algorithm for cone beam CT with a circular trajectory1,developed on a modern Graphics Processing Unit (GPU). The resulting tomographic backprojection system for 3D cone beam geometry combines speedup through algorithmic improvements provided by the hierarchical backprojection algorithm with speedup from a massively parallel hardware accelerator. For data parameters typical in diagnostic CT and using a mid-range GPU card, we report reconstruction speeds of up to 360 frames per second, and relative speedup of almost 6x compared to conventional backprojection on the same hardware. The significance of these results is twofold. First, they demonstrate that the reduction in operation counts demonstrated previously for the FHBP algorithm can be translated to a comparable run-time improvement in a massively parallel hardware implementation, while preserving stringent diagnostic image quality. Second, the dramatic speedup and throughput numbers achieved indicate the feasibility of systems based on this technology, which achieve real-time 3D reconstruction for state-of-the art diagnostic CT scanners with small footprint, high-reliability, and affordable cost.

Superluminous Spiral Galaxies

NASA Astrophysics Data System (ADS)

Ogle, Patrick M.; Lanz, Lauranne; Nader, Cyril; Helou, George

2016-02-01

We report the discovery of spiral galaxies that are as optically luminous as elliptical brightest cluster galaxies, with r-band monochromatic luminosity Lr = 8-14L* (4.3-7.5 × 1044 erg s-1). These super spiral galaxies are also giant and massive, with diameter D = 57-134 kpc and stellar mass Mstars = 0.3-3.4 × 1011M⊙. We find 53 super spirals out of a complete sample of 1616 SDSS galaxies with redshift z < 0.3 and Lr > 8L*. The closest example is found at z = 0.089. We use existing photometry to estimate their stellar masses and star formation rates (SFRs). The SDSS and Wide-field Infrared Survey Explorer colors are consistent with normal star-forming spirals on the blue sequence. However, the extreme masses and rapid SFRs of 5-65 M⊙ yr-1 place super spirals in a sparsely populated region of parameter space, above the star-forming main sequence of disk galaxies. Super spirals occupy a diverse range of environments, from isolation to cluster centers. We find four super spiral galaxy systems that are late-stage major mergers—a possible clue to their formation. We suggest that super spirals are a remnant population of unquenched, massive disk galaxies. They may eventually become massive lenticular galaxies after they are cut off from their gas supply and their disks fade.

Effects of grand unification interactions on weak symmetry breaking in supergravity theories

NASA Astrophysics Data System (ADS)

Moxhay, Peter; Yamamoto, Katsuji

Possible effects of grand unification interactions on SU(2) × U(1) breaking are investigated by explicitly considering a supersymmetric SU(5) model coupled to N = 1 supergravity. Some remarkable features concerning the effects of renormalization on the effective soft supersymmetry breaking terms of SU(5) in the GUT region MP - MG are clarified, which are relevant for determining the SU(3) × SU(2) × U(1) theory below MG. In particular, the (mass) 2 of the Higgs doublets, g Hm g2and g overlineHm g2, might become significantly small at M G (g H ⋍ g overlineH ≈ 0.1) through the effect of SU(5) couplings such as overlineHø EH . Then, gH can rather easily become negative below MG, so as to realize SU(2) × U(1) breaking naturally even for the "diet" top quark case ( mt ≈ 40 GeV). On the other hand, if g H ⋍ g overlineH ⋍ 1 at M G by neglecting the grand unification interactions, some careful tuning of μ32/ mg2 is required with an accuracy ⪅10 -2 to achieve SU(2) × U(1) breaking with "diet" top quark, though a mass term μ 32( overlineHH) may be present.

Type IIB supergravity solution for the T-dual of the η-deformed AdS 5 × S 5 superstring

NASA Astrophysics Data System (ADS)

Hoare, B.; Tseytlin, A. A.

2015-10-01

We find an exact type IIB supergravity solution that represents a one-parameter deformation of the T-dual of the AdS 5 × S 5 background (with T-duality applied in all 6 abelian bosonic isometric directions). The non-trivial fields are the metric, dilaton and RR 5-form only. The latter has remarkably simple "undeformed" form when written in terms of a "deformation-rotated" vielbein basis. An unusual feature of this solution is that the dilaton contains a linear dependence on the isometric coordinates of the metric precluding a straightforward reversal of T-duality. If we still formally dualize back, we find exactly the metric, B-field and product of dilaton with RR field strengths as recently extracted from the η-deformed AdS 5 × S 5 superstring action in arXiv:1507.04239. We also discuss similar solutions for deformed AdS n × S n backgrounds with n = 2 , 3. In the η → i limit we demonstrate that all these backgrounds can be interpreted as special limits of gauged WZW models and are also related to (a limit of) the Pohlmeyer-reduced models of the AdS n × S n superstrings.

YBa_2Cu_3O_{7-δ} : in pursuit of the ideal microstructure

NASA Astrophysics Data System (ADS)

Smith, D. S.; Suasmoro, S.; Lejeune, M.; Rabier, J.; Denanot, M. F.; Heintz, J. M.; Magro, C.; Bonnet, J. P.

1992-02-01

This paper examines the role of different factors in the microstructure of ceramic YBa2Cu3O{7-δ} with emphasis on its electrical response. In particular we discuss : 1. the effect of microstructural variations on j_c and ρ_{300}, 2. measurement of j_c, 3. the presence of minor phases and carbonates, 4. oxygen uptake and microcracks, 5. plastic deformation and related structural defects. Dans cet article, nous examinons d'une part la réponse électrique de céramiques supraconductrices massives de type YBa2Cu3O{7-δ} et d'autre part sa relation avec la microstructure. Nous présenterons successivement : 1. L'incidence de modifications microstructurales sur les valeurs de j_c et ρ_{300}, 2. les mesures expérimentales de j_c, 3. la présence de phases minoritaires et de carbonates, 4. la reprise d'oxygène et la microfissuration, 5. la déformation plastique et les défauts structuraux associés.

Joint inversions of two VTEM surveys using quasi-3D TDEM and 3D magnetic inversion algorithms

NASA Astrophysics Data System (ADS)

Kaminski, Vlad; Di Massa, Domenico; Viezzoli, Andrea

2016-05-01

In the current paper, we present results of a joint quasi-three-dimensional (quasi-3D) inversion of two versatile time domain electromagnetic (VTEM) datasets, as well as a joint 3D inversion of associated aeromagnetic datasets, from two surveys flown six years apart from one another (2007 and 2013) over a volcanogenic massive sulphide gold (VMS-Au) prospect in northern Ontario, Canada. The time domain electromagnetic (TDEM) data were inverted jointly using the spatially constrained inversion (SCI) approach. In order to increase the coherency in the model space, a calibration parameter was added. This was followed by a joint inversion of the total magnetic intensity (TMI) data extracted from the two surveys. The results of the inversions have been studied and matched with the known geology, adding some new valuable information to the ongoing mineral exploration initiative.

Quantitative ultrashort echo time imaging for assessment of massive iron overload at 1.5 and 3 Tesla.

PubMed

Krafft, Axel J; Loeffler, Ralf B; Song, Ruitian; Tipirneni-Sajja, Aaryani; McCarville, M Beth; Robson, Matthew D; Hankins, Jane S; Hillenbrand, Claudia M

2017-11-01

Hepatic iron content (HIC) quantification via transverse relaxation rate (R2*)-MRI using multi-gradient echo (mGRE) imaging is compromised toward high HIC or at higher fields due to the rapid signal decay. Our study aims at presenting an optimized 2D ultrashort echo time (UTE) sequence for R2* quantification to overcome these limitations. Two-dimensional UTE imaging was realized via half-pulse excitation and radial center-out sampling. The sequence includes chemically selective saturation pulses to reduce streaking artifacts from subcutaneous fat, and spatial saturation (sSAT) bands to suppress out-of-slice signals. The sequence employs interleaved multi-echo readout trains to achieve dense temporal sampling of rapid signal decays. Evaluation was done at 1.5 Tesla (T) and 3T in phantoms, and clinical applicability was demonstrated in five patients with biopsy-confirmed massively high HIC levels (>25 mg Fe/g dry weight liver tissue). In phantoms, the sSAT pulses were found to remove out-of-slice contamination, and R2* results were in excellent agreement to reference mGRE R2* results (slope of linear regression: 1.02/1.00 for 1.5/3T). UTE-based R2* quantification in patients with massive iron overload proved successful at both field strengths and was consistent with biopsy HIC values. The UTE sequence provides a means to measure R2* in patients with massive iron overload, both at 1.5T and 3T. Magn Reson Med 78:1839-1851, 2017. © 2017 Wiley Periodicals, Inc. © 2017 International Society for Magnetic Resonance in Medicine.

Large-scale high density 3D AMT for mineral exploration — A case history from volcanic massive sulfide Pb-Zn deposit with 2000 AMT sites

NASA Astrophysics Data System (ADS)

Chen, R.; Chen, S.; He, L.; Yao, H.; Li, H.; Xi, X.; Zhao, X.

2017-12-01

EM method plays a key role in volcanic massive sulfide (VMS) deposit which is with high grade and high economic value. However, the performance of high density 3D AMT in detecting deep concealed VMS targets is not clear. The size of a typical VMS target is less than 100 m x 100 m x 50 m, it's a challenge task to find it with large depth. We carried a test in a VMS Pb-Zn deposit using high density 3D AMT with site spacing as 20 m and profile spacing as 40 - 80 m. About 2000 AMT sites were acquired in an area as 2000 m x 1500 m. Then we used a sever with 8 CPUs (Intel Xeon E7-8880 v3, 2.3 GHz, 144 cores), 2048 GB RAM, and 40 TB disk array to invert above 3D AMT sites using integral equation forward modeling and re-weighted conjugated-gradient inversion. The depth of VMS ore body is about 600 m and the size of the ore body is about 100 x 100 x 20m with dip angle about 45 degree. We finds that it's very hard to recover the location and shape of the ore body by 3D AMT inversion even using the data of all AMT sites and frequencies. However, it's possible to recover the location and shape of the deep concealed ore body if we adjust the inversion parameters carefully. A new set of inversion parameter needs to be find for high density 3D AMT data set and the inversion parameters working good for Dublin Secret Model II (DSM 2) is not suitable for our real data. This problem may be caused by different data density and different number of frequency. We find a set of good inversion parameter by comparing the shape and location of ore body with inversion result and trying different inversion parameters. And the application of new inversion parameter in nearby area with high density AMT sites shows that the inversion result is improved greatly.

Anomaly-corrected supersymmetry algebra and supersymmetric holographic renormalization

NASA Astrophysics Data System (ADS)

An, Ok Song

2017-12-01

We present a systematic approach to supersymmetric holographic renormalization for a generic 5D N=2 gauged supergravity theory with matter multiplets, including its fermionic sector, with all gauge fields consistently set to zero. We determine the complete set of supersymmetric local boundary counterterms, including the finite counterterms that parameterize the choice of supersymmetric renormalization scheme. This allows us to derive holographically the superconformal Ward identities of a 4D superconformal field theory on a generic background, including the Weyl and super-Weyl anomalies. Moreover, we show that these anomalies satisfy the Wess-Zumino consistency condition. The super-Weyl anomaly implies that the fermionic operators of the dual field theory, such as the supercurrent, do not transform as tensors under rigid supersymmetry on backgrounds that admit a conformal Killing spinor, and their anticommutator with the conserved supercharge contains anomalous terms. This property is explicitly checked for a toy model. Finally, using the anomalous transformation of the supercurrent, we obtain the anomaly-corrected supersymmetry algebra on curved backgrounds admitting a conformal Killing spinor.

Development of massive multilevel molecular dynamics simulation program, Platypus (PLATform for dYnamic Protein Unified Simulation), for the elucidation of protein functions.

PubMed

Takano, Yu; Nakata, Kazuto; Yonezawa, Yasushige; Nakamura, Haruki

2016-05-05

A massively parallel program for quantum mechanical-molecular mechanical (QM/MM) molecular dynamics simulation, called Platypus (PLATform for dYnamic Protein Unified Simulation), was developed to elucidate protein functions. The speedup and the parallelization ratio of Platypus in the QM and QM/MM calculations were assessed for a bacteriochlorophyll dimer in the photosynthetic reaction center (DIMER) on the K computer, a massively parallel computer achieving 10 PetaFLOPs with 705,024 cores. Platypus exhibited the increase in speedup up to 20,000 core processors at the HF/cc-pVDZ and B3LYP/cc-pVDZ, and up to 10,000 core processors by the CASCI(16,16)/6-31G** calculations. We also performed excited QM/MM-MD simulations on the chromophore of Sirius (SIRIUS) in water. Sirius is a pH-insensitive and photo-stable ultramarine fluorescent protein. Platypus accelerated on-the-fly excited-state QM/MM-MD simulations for SIRIUS in water, using over 4000 core processors. In addition, it also succeeded in 50-ps (200,000-step) on-the-fly excited-state QM/MM-MD simulations for the SIRIUS in water. © 2016 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc.

Massive parallelization of a 3D finite difference electromagnetic forward solution using domain decomposition methods on multiple CUDA enabled GPUs

NASA Astrophysics Data System (ADS)

Schultz, A.

2010-12-01

3D forward solvers lie at the core of inverse formulations used to image the variation of electrical conductivity within the Earth's interior. This property is associated with variations in temperature, composition, phase, presence of volatiles, and in specific settings, the presence of groundwater, geothermal resources, oil/gas or minerals. The high cost of 3D solutions has been a stumbling block to wider adoption of 3D methods. Parallel algorithms for modeling frequency domain 3D EM problems have not achieved wide scale adoption, with emphasis on fairly coarse grained parallelism using MPI and similar approaches. The communications bandwidth as well as the latency required to send and receive network communication packets is a limiting factor in implementing fine grained parallel strategies, inhibiting wide adoption of these algorithms. Leading Graphics Processor Unit (GPU) companies now produce GPUs with hundreds of GPU processor cores per die. The footprint, in silicon, of the GPU's restricted instruction set is much smaller than the general purpose instruction set required of a CPU. Consequently, the density of processor cores on a GPU can be much greater than on a CPU. GPUs also have local memory, registers and high speed communication with host CPUs, usually through PCIe type interconnects. The extremely low cost and high computational power of GPUs provides the EM geophysics community with an opportunity to achieve fine grained (i.e. massive) parallelization of codes on low cost hardware. The current generation of GPUs (e.g. NVidia Fermi) provides 3 billion transistors per chip die, with nearly 500 processor cores and up to 6 GB of fast (DDR5) GPU memory. This latest generation of GPU supports fast hardware double precision (64 bit) floating point operations of the type required for frequency domain EM forward solutions. Each Fermi GPU board can sustain nearly 1 TFLOP in double precision, and multiple boards can be installed in the host computer system. We describe our ongoing efforts to achieve massive parallelization on a novel hybrid GPU testbed machine currently configured with 12 Intel Westmere Xeon CPU cores (or 24 parallel computational threads) with 96 GB DDR3 system memory, 4 GPU subsystems which in aggregate contain 960 NVidia Tesla GPU cores with 16 GB dedicated DDR3 GPU memory, and a second interleved bank of 4 GPU subsystems containing in aggregate 1792 NVidia Fermi GPU cores with 12 GB dedicated DDR5 GPU memory. We are applying domain decomposition methods to a modified version of Weiss' (2001) 3D frequency domain full physics EM finite difference code, an open source GPL licensed f90 code available for download from www.OpenEM.org. This will be the core of a new hybrid 3D inversion that parallelizes frequencies across CPUs and individual forward solutions across GPUs. We describe progress made in modifying the code to use direct solvers in GPU cores dedicated to each small subdomain, iteratively improving the solution by matching adjacent subdomain boundary solutions, rather than iterative Krylov space sparse solvers as currently applied to the whole domain.

Bed bugs can cause severe anaemia in adults.

PubMed

Paulke-Korinek, Maria; Széll, Marton; Laferl, Hermann; Auer, Herbert; Wenisch, Christoph

2012-06-01

A 60-year-old woman and her 67-year-old male partner, admitted for pneumonia and non-ST elevation myocardial infarction, respectively, had severe anaemia (Hb 5.3 and 5.2 g/dL, respectively), as a result from massive infestation with Cimex lectularius. After two erythrocyte transfusions and thorough decontamination, their clinical course was unremarkable.

Einstein-Cartan calculus for exceptional geometry

NASA Astrophysics Data System (ADS)

Godazgar, Hadi; Godazgar, Mahdi; Nicolai, Hermann

2014-06-01

In this paper we establish and clarify the link between the recently found E7(7) generalised geometric structures, which are based on the SU(8) invariant reformulation of D = 11 supergravity proposed long ago, and newer results obtained in the framework of recent approaches to generalised geometry, where E7(7) duality is built in and manifest from the outset. In making this connection, the so-called generalised vielbein postulate plays a key role. We explicitly show how this postulate can be used to define an E7(7) valued affine connection and an associated covariant derivative, which yields a generalised curvature tensor for the E7(7) based exceptional geometry. The analysis of the generalised vielbein postulate also provides a natural explanation for the emergence of the embedding tensor from higher dimensions.

Search for supersymmetry via associated production of charginos and neutralinos in final states with three leptons.

PubMed

Abazov, V M; Abbott, B; Abolins, M; Acharya, B S; Adams, M; Adams, T; Agelou, M; Agram, J-L; Ahn, S H; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Anastasoaie, M; Andeen, T; Anderson, S; Andrieu, B; Arnoud, Y; Askew, A; Asman, B; Assis Jesus, A C S; Atramentov, O; Autermann, C; Avila, C; Badaud, F; Baden, A; Baldin, B; Balm, P W; Banerjee, S; Barberis, E; Bargassa, P; Baringer, P; Barnes, C; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Bean, A; Beauceron, S; Begel, M; Bellavance, A; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Binder, M; Biscarat, C; Black, K M; Blackler, I; Blazey, G; Blekman, F; Blessing, S; Bloch, D; Blumenschein, U; Boehnlein, A; Boeriu, O; Bolton, T A; Borcherding, F; Borissov, G; Bos, K; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Buchanan, N J; Buchholz, D; Buehler, M; Buescher, V; Burdin, S; Burnett, T H; Busato, E; Buszello, C P; Butler, J M; Cammin, J; Caron, S; Carvalho, W; Casey, B C K; Cason, N M; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chandra, A; Chapin, D; Charles, F; Cheu, E; Cho, D K; Choi, S; Choudhary, B; Christiansen, T; Christofek, L; Claes, D; Clément, B; Clément, C; Coadou, Y; Cooke, M; Cooper, W E; Coppage, D; Corcoran, M; Cothenet, A; Cousinou, M-C; Cox, B; Crépé-Renaudin, S; Cutts, D; da Motta, H; Davies, B; Davies, G; Davis, G A; De, K; de Jong, P; de Jong, S J; De La Cruz-Burelo, E; Martins, C De Oliveira; Dean, S; Degenhardt, J D; Déliot, F; Demarteau, M; Demina, R; Demine, P; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Doidge, M; Dong, H; Doulas, S; Dudko, L V; Duflot, L; Dugad, S R; Duperrin, A; Dyer, J; Dyshkant, A; Eads, M; Edmunds, D; Edwards, T; Ellison, J; Elmsheuser, J; Elvira, V D; Eno, S; Ermolov, P; Eroshin, O V; Estrada, J; Evans, H; Evdokimov, A; Evdokimov, V N; Fast, J; Fatakia, S N; Feligioni, L; Ferapontov, A V; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fleck, I; Fortner, M; Fox, H; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Gallas, E; Galyaev, E; Garcia, C; Garcia-Bellido, A; Gardner, J; Gavrilov, V; Gay, P; Gelé, D; Gelhaus, R; Genser, K; Gerber, C E; Gershtein, Y; Gillberg, D; Ginther, G; Golling, T; Gollub, N; Gómez, B; Gounder, K; Goussiou, A; Grannis, P D; Greder, S; Greenlee, H; Greenwood, Z D; Gregores, E M; Gris, Ph; Grivaz, J-F; Groer, L; Grünendahl, S; Grünewald, M W; Gurzhiev, S N; Gutierrez, G; Gutierrez, P; Haas, A; Hadley, N J; Hagopian, S; Hall, I; Hall, R E; Han, C; Han, L; Hanagaki, K; Harder, K; Harel, A; Harrington, R; Hauptman, J M; Hauser, R; Hays, J; Hebbeker, T; Hedin, D; Heinmiller, J M; Heinson, A P; Heintz, U; Hensel, C; Hesketh, G; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hohlfeld, M; Hong, S J; Hooper, R; Houben, P; Hu, Y; Huang, J; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jain, V; Jakobs, K; Jenkins, A; Jesik, R; Johns, K; Johnson, M; Jonckheere, A; Jonsson, P; Juste, A; Käfer, D; Kahn, S; Kajfasz, E; Kalinin, A M; Kalk, J; Karmanov, D; Kasper, J; Kau, D; Kaur, R; Kehoe, R; Kermiche, S; Kesisoglou, S; Khanov, A; Kharchilava, A; Kharzheev, Y M; Kim, H; Kim, T J; Klima, B; Kohli, J M; Kopal, M; Korablev, V M; Kotcher, J; Kothari, B; Koubarovsky, A; Kozelov, A V; Kozminski, J; Kryemadhi, A; Krzywdzinski, S; Kulik, Y; Kumar, A; Kunori, S; Kupco, A; Kurca, T; Kvita, J; Lager, S; Lahrichi, N; Landsberg, G; Lazoflores, J; Bihan, A-C Le; Lebrun, P; Lee, W M; Leflat, A; Lehner, F; Leonidopoulos, C; Leveque, J; Lewis, P; Li, J; Li, Q Z; Lima, J G R; Lincoln, D; Linn, S L; Linnemann, J; Lipaev, V V; Lipton, R; Lobo, L; Lobodenko, A; Lokajicek, M; Lounis, A; Love, P; Lubatti, H J; Lueking, L; Lynker, M; Lyon, A L; Maciel, A K A; Madaras, R J; Mättig, P; Magass, C; Magerkurth, A; Magnan, A-M; Makovec, N; Mal, P K; Malbouisson, H B; Malik, S; Malyshev, V L; Mao, H S; Maravin, Y; Martens, M; Mattingly, S E K; Mayorov, A A; McCarthy, R; McCroskey, R; Meder, D; Melnitchouk, A; Mendes, A; Merkin, M; Merritt, K W; Meyer, A; Meyer, J; Michaut, M; Miettinen, H; Mitrevski, J; Molina, J; Mondal, N K; Moore, R W; Muanza, G S; Mulders, M; Mutaf, Y D; Nagy, E; Narain, M; Naumann, N A; Neal, H A; Negret, J P; Nelson, S; Neustroev, P; Noeding, C; Nomerotski, A; Novaes, S F; Nunnemann, T; Nurse, E; O'dell, V; O'neil, D C; Oguri, V; Oliveira, N; Oshima, N; Otero Y Garzón, G J; Padley, P; Parashar, N; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Pawloski, G; Perea, P M; Perez, E; Pétroff, P; Petteni, M; Piegaia, R; Pleier, M-A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pompos, A; Pope, B G; Prado da Silva, W L; Prosper, H B; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rani, K J; Ranjan, K; Rapidis, P A; Ratoff, P N; Reucroft, S; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Robinson, S; Rodrigues, R F; Royon, C; Rubinov, P; Ruchti, R; Rud, V I; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Santoro, A; Savage, G; Sawyer, L; Scanlon, T; Schaile, D; Schamberger, R D; Schellman, H; Schieferdecker, P; Schmitt, C; Schwanenberger, C; Schwartzman, A; Schwienhorst, R; Sengupta, S; Severini, H; Shabalina, E; Shamim, M; Shary, V; Shchukin, A A; Shephard, W D; Shivpuri, R K; Shpakov, D; Sidwell, R A; Simak, V; Sirotenko, V; Skubic, P; Slattery, P; Smith, R P; Smolek, K; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Song, X; Sonnenschein, L; Sopczak, A; Sosebee, M; Soustruznik, K; Souza, M; Spurlock, B; Stanton, N R; Stark, J; Steele, J; Stevenson, K; Stolin, V; Stone, A; Stoyanova, D A; Strandberg, J; Strang, M A; Strauss, M; Ströhmer, R; Strom, D; Strovink, M; Stutte, L; Sumowidagdo, S; Sznajder, A; Talby, M; Tamburello, P; Taylor, W; Telford, P; Temple, J; Tomoto, M; Toole, T; Torborg, J; Towers, S; Trefzger, T; Trincaz-Duvoid, S; Tuchming, B; Tully, C; Turcot, A S; Tuts, P M; Uvarov, L; Uvarov, S; Uzunyan, S; Vachon, B; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vartapetian, A; Vasilyev, I A; Vaupel, M; Verdier, P; Vertogradov, L S; Verzocchi, M; Villeneuve-Seguier, F; Vlimant, J-R; Von Toerne, E; Vreeswijk, M; Vu Anh, T; Wahl, H D; Wang, L; Warchol, J; Watts, G; Wayne, M; Weber, M; Weerts, H; Wegner, M; Wermes, N; White, A; White, V; Wicke, D; Wijngaarden, D A; Wilson, G W; Wimpenny, S J; Wittlin, J; Wobisch, M; Womersley, J; Wood, D R; Wyatt, T R; Xu, Q; Xuan, N; Yacoob, S; Yamada, R; Yan, M; Yasuda, T; Yatsunenko, Y A; Yen, Y; Yip, K; Yoo, H D; Youn, S W; Yu, J; Yurkewicz, A; Zabi, A; Zatserklyaniy, A; Zdrazil, M; Zeitnitz, C; Zhang, D; Zhang, X; Zhao, T; Zhao, Z; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zieminski, A; Zitoun, R; Zutshi, V; Zverev, E G

2005-10-07

A search for associated production of charginos and neutralinos is performed using data recorded with the D0 detector at a pp center-of-mass energy of 1.96 TeV at the Fermilab Tevatron Collider. This analysis considers final states with missing transverse energy and three charged leptons, of which at least two are electrons or muons. No evidence for supersymmetry is found in a data set corresponding to an integrated luminosity of 320 pb-1. Limits on the product of the production cross section and leptonic branching fraction are set. For the minimal supergravity model, a chargino lower mass limit of 117 GeV at the 95% C.L. is derived in regions of parameter space with enhanced leptonic branching fractions.

CERN Winter School on Supergravity, Strings, and Gauge Theory 2010

ScienceCinema

None

2018-05-15

The CERN Winter School on Supergravity, Strings, and Gauge Theory is the analytic continuation of the yearly training school of the former EC-RTN string network Constituents, Fundamental Forces and Symmetries of the Universe. The 2010 edition of the school is supported and organized by the CERN Theory Divison, and will take place from Monday January 25 to Friday January 29, at CERN. As its predecessors, this school is meant primarily for training of doctoral students and young postdoctoral researchers in recent developments in theoretical high-energy physics and string theory. The programme of the school will consist of five series of pedagogical lectures, complemented by tutorial discussion sessions in the afternoons. Previous schools in this series were organized in 2005 at SISSA in Trieste, and in 2006, 2007, 2008, and 2009 at CERN, Geneva.

Supergravity, complex parameters and the Janis-Newman algorithm

NASA Astrophysics Data System (ADS)

Erbin, Harold; Heurtier, Lucien

2015-08-01

The Demiański-Janis-Newman (DJN) algorithm is an original solution generating technique. For a long time it has been limited to producing rotating solutions, restricted to the case of a metric and real scalar fields, despite the fact that Demiański extended it to include more parameters such as a NUT charge. Recently two independent prescriptions have been given for extending the algorithm to gauge fields and thus electrically charged configurations. In this paper we aim to end setting up the algorithm by providing a missing but important piece, which is how the transformation is applied to complex scalar fields. We illustrate our proposal through several examples taken from N = 2 supergravity, including the stationary BPS solutions from Behrndt et al and Sen's axion-dilaton rotating black hole. Moreover we discuss solutions that include pairs of complex parameters, such as the mass and the NUT charge, or the electric and magnetic charges, and we explain how to perform the algorithm in this context (with the example of Kerr-Newman-Taub-NUT and dyonic Kerr-Newman black holes). The final formulation of the DJN algorithm can possibly handle solutions with five of the six Plebański-Demiański parameters along with any type of bosonic fields with spin less than two (exemplified with the stationary Israel-Wilson-Perjes solutions). This provides all the necessary tools for applications to general matter-coupled gravity and to (gauged) supergravity.

The early phases of galaxy clusters formation in IR: coupling hydrodynamical simulations with GRASIL-3D

NASA Astrophysics Data System (ADS)

Granato, Gian Luigi; Ragone-Figueroa, Cinthia; Domínguez-Tenreiro, Rosa; Obreja, Aura; Borgani, Stefano; De Lucia, Gabriella; Murante, Giuseppe

2015-06-01

We compute and study the infrared and sub-mm properties of high-redshift (z ≳ 1) simulated clusters and protoclusters. The results of a large set of hydrodynamical zoom-in simulations including active galactic nuclei (AGN) feedback, have been treated with the recently developed radiative transfer code GRASIL-3D, which accounts for the effect of dust reprocessing in an arbitrary geometry. Here, we have slightly generalized the code to adapt it to the present purpose. Then we have post-processed boxes of physical size 2 Mpc encompassing each of the 24 most massive clusters identified at z = 0, at several redshifts between 0.5 and 3, producing IR and sub-mm mock images of these regions and spectral energy distributions (SEDs) of the radiation coming out from them. While this field is in its infancy from the observational point of view, rapid development is expected in the near future thanks to observations performed in the far-IR and sub-mm bands. Notably, we find that in this spectral regime our prediction are little affected by the assumption required by this post-processing, and the emission is mostly powered by star formation (SF) rather than accretion on to super massive black hole (SMBH). The comparison with the little observational information currently available, highlights that the simulated cluster regions never attain the impressive star formation rates suggested by these observations. This problem becomes more intriguing taking into account that the brightest cluster galaxies (BCGs) in the same simulations turn out to be too massive. It seems that the interplay between the feedback schemes and the star formation model should be revised, possibly incorporating a positive feedback mode.

Exp(1076) Shades of Black: Aspects of Black Hole Microstates

NASA Astrophysics Data System (ADS)

Vasilakis, Orestis

In this thesis we examine smooth supergravity solutions known as "microstate geometries". These solutions have neither a horizon, nor a singularity, yet they have the same asymptotic structure and conserved charges as black holes. Specifically we study supersymmetric and extremal non-supersymmetric solutions. The goal of this program is to construct enough microstates to account for the correct scaling behavior of the black hole entropy with respect to the charges within the supergravity approximation. For supersymmetric systems that are ⅛-BPS, microstate geometries account so far only for Q5/4 of the total entropy S ˜ Q3/2, while for non-supersymmetric systems the known microstate geometries are sporadic. For the supersymmetric case we construct solutions with three and four charges. Five-dimensional systems with three and four charges are ⅛-BPS. Thus they admit macroscopic horizons making the supergravity approximation valid. For the three-charge case we present some steps towards the construction of the superstratum, a microstate geometry depending on arbitrary functions of two variables, which is expected to provide the necessary entropy for this class of solutions. Specifically we construct multiple concentric solutions with three electric and two dipole magnetic charges which depend on arbitrary functions of two variables and examine their properties. These solutions have no KKM charge and thus are singular. For the four-charge case we construct microstate geometries by extending results available in the literature for three charges. We find smooth solutions in terms of bubbled geometries with ambipolar Gibbons-Hawking base space and by constructing the relevant supertubes. In the non-supersymmetric case we work with a three-charge system of extremal black holes known as almost-BPS, which provides a controlled way of breaking sypersymmetry. By using supertubes we construct the first systematic example of a family of almost-BPS microstate geometries and examine the moduli space of solutions. Furthermore by using brane probe analysis we show that, despite the breaking of supersymmetry, almost-BPS solutions receive no quantum corrections and thus must be subject to some kind of non-renormalization theorem.

Higgs funnel region of supersymmetric dark matter for small tan⁡β and renormalization group effects on pseudoscalar Higgs boson with scalar mass nonuniversality

NASA Astrophysics Data System (ADS)

Chattopadhyay, Utpal; Das, Debottam

2009-02-01

A nonuniversal scalar mass supergravity type of model is explored where the first two generations of scalars and the third generation of sleptons may be very massive. The lighter or vanishing third generation of squarks as well as Higgs scalars at the unification scale cause the radiative electroweak symmetry breaking constraint to be less prohibitive. Thus, both flavor-changing neutral-current/CP-violation problems as well as the naturalness problem are within control. We identify a large slepton mass effect in the renormalization group equations of mHD2 (for the down type of Higgs) that may turn the latter negative at the electroweak scale even for a small tan⁡β. A hyperbolic branch/focus pointlike effect is found for mA2 that may result in very light Higgs spectra. The lightest stable particle is dominantly a b-ino that pair annihilates via Higgs exchange, giving rise to a Wilkinson Microwave Anisotropy Probe satisfied relic density region for all tan⁡β. Detection prospects of such lightest stable particles in the upcoming dark matter experiments both of direct and indirect types (photon flux) are interesting. The Higgs bosons and the third generation of squarks are light in this scenario and these may be easily probed besides charginos and neutralinos in the early runs of the Large Hadron Collider.

3D Data Denoising via Nonlocal Means Filter by Using Parallel GPU Strategies

PubMed Central

Cuomo, Salvatore; De Michele, Pasquale; Piccialli, Francesco

2014-01-01

Nonlocal Means (NLM) algorithm is widely considered as a state-of-the-art denoising filter in many research fields. Its high computational complexity leads researchers to the development of parallel programming approaches and the use of massively parallel architectures such as the GPUs. In the recent years, the GPU devices had led to achieving reasonable running times by filtering, slice-by-slice, and 3D datasets with a 2D NLM algorithm. In our approach we design and implement a fully 3D NonLocal Means parallel approach, adopting different algorithm mapping strategies on GPU architecture and multi-GPU framework, in order to demonstrate its high applicability and scalability. The experimental results we obtained encourage the usability of our approach in a large spectrum of applicative scenarios such as magnetic resonance imaging (MRI) or video sequence denoising. PMID:25045397

Advances in three-dimensional integral imaging: sensing, display, and applications [Invited].

PubMed

Xiao, Xiao; Javidi, Bahram; Martinez-Corral, Manuel; Stern, Adrian

2013-02-01

Three-dimensional (3D) sensing and imaging technologies have been extensively researched for many applications in the fields of entertainment, medicine, robotics, manufacturing, industrial inspection, security, surveillance, and defense due to their diverse and significant benefits. Integral imaging is a passive multiperspective imaging technique, which records multiple two-dimensional images of a scene from different perspectives. Unlike holography, it can capture a scene such as outdoor events with incoherent or ambient light. Integral imaging can display a true 3D color image with full parallax and continuous viewing angles by incoherent light; thus it does not suffer from speckle degradation. Because of its unique properties, integral imaging has been revived over the past decade or so as a promising approach for massive 3D commercialization. A series of key articles on this topic have appeared in the OSA journals, including Applied Optics. Thus, it is fitting that this Commemorative Review presents an overview of literature on physical principles and applications of integral imaging. Several data capture configurations, reconstruction, and display methods are overviewed. In addition, applications including 3D underwater imaging, 3D imaging in photon-starved environments, 3D tracking of occluded objects, 3D optical microscopy, and 3D polarimetric imaging are reviewed.

A new photometric study of the triple star system EF Draconis

NASA Astrophysics Data System (ADS)

Yang, Yuan-Gui

2012-04-01

We present new charge-coupled device (CCD) photometry for the triple star EF Draconis, obtained in 2009 and 2011. Using the updated Wilson-Devinney program, the photometric solutions were deduced from two sets of light curves. The results indicate that EF Dra is an A-type W UMa binary with a contact degree of f = 46.7%(±0.6%) and a third light of l3 ≃ 1.5%. Through analyzing the O — C curve, it is found that the orbital period shows a long-time increase with a light-time orbit. The period, semi-amplitude and eccentricity of the third body are Pmod = 17.20(±0.18) yr, A = 0.0039d(±0.0002d) and e = 0.49(±0.02) respectively. This kind of tertiary companion may extract angular momentum from the central system. The orbital period of EF Dra secularly increases at a rate of dP/dt = +3.72(±0.07) × 10-7 d yr-1, which may be interpreted by mass transfer from the less massive to the more massive component. As period increases, the separation between components may increase, which will cause the contact degree to decrease. With mass transferring, the spin angular momentum will increase, while the orbital angular momentum will decrease. Only if the contact configuration would merge at could this kind of deep-contact binary with period increasing, such as EF Dra, evolve into a rapidly-rotating single star.

Massive Star Formation of the SGR a East H (sub II) Regions Near the Galactic Center

NASA Technical Reports Server (NTRS)

Yusef-Zadeh, F.; Lacy, J. H.; Wardle, M.; Whitney, B.; Bushouse, H.; Roberts, D. A.; Arendt, R. G.

2010-01-01

A group of four compact H II regions associated with the well-known 50 km/s molecular cloud is the closest site of on-going star formation to the dynamical center of the Galaxy, at a projected distance of approximately 6 pc. We present a study of ionized gas based on the [Ne II] (12.8 micron) line, as well as multi-frequency radio continuum, Hubble Space Telescope Pa alpha, and Spitzer Infrared Array Camera observations of the most compact member of the H II group, Sgr A East H II D. The radio continuum image at 6 cm shows that this source breaks up into two equally bright ionized features, D1 and D2. The spectral energy distribution of the D source is consistent with it being due to a 25 =/- 3 solar mass star with a luminosity of 8 +/- 3 x 10(exp 4) Solar luminosity . The inferred mass, effective temperature of the UV source, and the ionization rate are compatible with a young O9-B0 star. The ionized features D1 and D2 are considered to be ionized by UV radiation collimated by an accretion disk. We consider that the central massive star photoevaporates its circumstellar disk on a timescale of 3x (exp 4) years giving a mass flux approximately 3 x 10(exp -5) Solar Mass / year and producing the ionized material in D1 and D2 expanding in an inhomogeneous medium. The ionized gas kinematics, as traced by the [Ne II] emission, is difficult to interpret, but it could be explained by the interaction of a bipolar jet with surrounding gas along with what appears to be a conical wall of lower velocity gas. The other H II regions, Sgr A East A-C, have morphologies and kinematics that more closely resemble cometary flows seen in other compact H II regions, where gas moves along a paraboloidal surface formed by the interaction of a stellar wind with a molecular cloud.

Satisfying the Einstein–Podolsky–Rosen criterion with massive particles

PubMed Central

Peise, J.; Kruse, I.; Lange, K.; Lücke, B.; Pezzè, L.; Arlt, J.; Ertmer, W.; Hammerer, K.; Santos, L.; Smerzi, A.; Klempt, C.

2015-01-01

In 1935, Einstein, Podolsky and Rosen (EPR) questioned the completeness of quantum mechanics by devising a quantum state of two massive particles with maximally correlated space and momentum coordinates. The EPR criterion qualifies such continuous-variable entangled states, where a measurement of one subsystem seemingly allows for a prediction of the second subsystem beyond the Heisenberg uncertainty relation. Up to now, continuous-variable EPR correlations have only been created with photons, while the demonstration of such strongly correlated states with massive particles is still outstanding. Here we report on the creation of an EPR-correlated two-mode squeezed state in an ultracold atomic ensemble. The state shows an EPR entanglement parameter of 0.18(3), which is 2.4 s.d. below the threshold 1/4 of the EPR criterion. We also present a full tomographic reconstruction of the underlying many-particle quantum state. The state presents a resource for tests of quantum nonlocality and a wide variety of applications in the field of continuous-variable quantum information and metrology. PMID:26612105

Satisfying the Einstein-Podolsky-Rosen criterion with massive particles.

PubMed

Peise, J; Kruse, I; Lange, K; Lücke, B; Pezzè, L; Arlt, J; Ertmer, W; Hammerer, K; Santos, L; Smerzi, A; Klempt, C

2015-11-27

In 1935, Einstein, Podolsky and Rosen (EPR) questioned the completeness of quantum mechanics by devising a quantum state of two massive particles with maximally correlated space and momentum coordinates. The EPR criterion qualifies such continuous-variable entangled states, where a measurement of one subsystem seemingly allows for a prediction of the second subsystem beyond the Heisenberg uncertainty relation. Up to now, continuous-variable EPR correlations have only been created with photons, while the demonstration of such strongly correlated states with massive particles is still outstanding. Here we report on the creation of an EPR-correlated two-mode squeezed state in an ultracold atomic ensemble. The state shows an EPR entanglement parameter of 0.18(3), which is 2.4 s.d. below the threshold 1/4 of the EPR criterion. We also present a full tomographic reconstruction of the underlying many-particle quantum state. The state presents a resource for tests of quantum nonlocality and a wide variety of applications in the field of continuous-variable quantum information and metrology.

Satisfying the Einstein-Podolsky-Rosen criterion with massive particles

NASA Astrophysics Data System (ADS)

Peise, J.; Kruse, I.; Lange, K.; Lücke, B.; Pezzè, L.; Arlt, J.; Ertmer, W.; Hammerer, K.; Santos, L.; Smerzi, A.; Klempt, C.

2015-11-01

In 1935, Einstein, Podolsky and Rosen (EPR) questioned the completeness of quantum mechanics by devising a quantum state of two massive particles with maximally correlated space and momentum coordinates. The EPR criterion qualifies such continuous-variable entangled states, where a measurement of one subsystem seemingly allows for a prediction of the second subsystem beyond the Heisenberg uncertainty relation. Up to now, continuous-variable EPR correlations have only been created with photons, while the demonstration of such strongly correlated states with massive particles is still outstanding. Here we report on the creation of an EPR-correlated two-mode squeezed state in an ultracold atomic ensemble. The state shows an EPR entanglement parameter of 0.18(3), which is 2.4 s.d. below the threshold 1/4 of the EPR criterion. We also present a full tomographic reconstruction of the underlying many-particle quantum state. The state presents a resource for tests of quantum nonlocality and a wide variety of applications in the field of continuous-variable quantum information and metrology.

Unitarity problems in 3D gravity theories

NASA Astrophysics Data System (ADS)

Alkac, Gokhan; Basanisi, Luca; Kilicarslan, Ercan; Tekin, Bayram

2017-07-01

We revisit the problem of the bulk-boundary unitarity clash in 2 +1 -dimensional gravity theories, which has been an obstacle in providing a viable dual two-dimensional conformal field theory for bulk gravity in anti-de Sitter (AdS) spacetime. Chiral gravity, which is a particular limit of cosmological topologically massive gravity (TMG), suffers from perturbative log-modes with negative energies inducing a nonunitary logarithmic boundary field theory. We show here that any f (R ) extension of TMG does not improve the situation. We also study the perturbative modes in the metric formulation of minimal massive gravity—originally constructed in a first-order formulation—and find that the massive mode has again negative energy except in the chiral limit. We comment on this issue and also discuss a possible solution to the problem of negative-energy modes. In any of these theories, the infinitesimal dangerous deformations might not be integrable to full solutions; this suggests a linearization instability of AdS spacetime in the direction of the perturbative log-modes.

World sheet instantons via the Myers effect and Script N = 1* quiver superpotentials

NASA Astrophysics Data System (ADS)

Hollowood, Timothy J.; Kumar, S. Prem

2002-10-01

In this note we explore the stringy interpretation of non-perturbative effects in Script N = 1* deformations of the Ak-1 quiver models. For certain types of deformations we argue that the massive vacua are described by Nk fractional D3-branes at the orbifold polarizing into k concentric 5-brane spheres each carrying fractional brane charge. The polarization of the D3-branes induces a polarization of D-instantons into string world-sheets wrapped on the Myers spheres. We show that the superpotentials in these models are indeed generated by these world-sheet instantons. We point out that for certain parameter values the condensates yield the exact superpotential for a relevant deformation of the Klebanov-Witten conifold theory.

Supergravity and the Unification of the Laws of Physics

ERIC Educational Resources Information Center

Freedman, Daniel Z.; van Nieuwenhuizen, Peter

1978-01-01

In this new theory the gravitational force arises from a symmetry relating particles with vastly different properties. The ultimate result may be a unified theory of all the basic forces in nature. (Author/BB)

Compact holographic optical neural network system for real-time pattern recognition

NASA Astrophysics Data System (ADS)

Lu, Taiwei; Mintzer, David T.; Kostrzewski, Andrew A.; Lin, Freddie S.

1996-08-01

One of the important characteristics of artificial neural networks is their capability for massive interconnection and parallel processing. Recently, specialized electronic neural network processors and VLSI neural chips have been introduced in the commercial market. The number of parallel channels they can handle is limited because of the limited parallel interconnections that can be implemented with 1D electronic wires. High-resolution pattern recognition problems can require a large number of neurons for parallel processing of an image. This paper describes a holographic optical neural network (HONN) that is based on high- resolution volume holographic materials and is capable of performing massive 3D parallel interconnection of tens of thousands of neurons. A HONN with more than 16,000 neurons packaged in an attache case has been developed. Rotation- shift-scale-invariant pattern recognition operations have been demonstrated with this system. System parameters such as the signal-to-noise ratio, dynamic range, and processing speed are discussed.

Gravitational wave from dark sector with dark pion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsumura, Koji; Yamada, Masatoshi; Yamaguchi, Yuya, E-mail: ko2@gauge.scphys.kyoto-u.ac.jp, E-mail: m.yamada@thphys.uni-heidelberg.de, E-mail: yy@particle.sci.hokudai.ac.jp

In this work, we investigate the spectra of gravitational waves produced by chiral symmetry breaking in dark quantum chromodynamics (dQCD) sector. The dark pion (π) can be a dark matter candidate as weakly interacting massive particle (WIMP) or strongly interacting massive particle (SIMP). For a WIMP scenario, we introduce the dQCD sector coupled to the standard model (SM) sector with classical scale invariance and investigate the annihilation process of the dark pion via the 2π → 2 SM process. For a SIMP scenario, we investigate the 3π → 2π annihilation process of the dark pion as a SIMP using chiralmore » perturbation theory. We find that in the WIMP scenario the gravitational wave background spectra can be observed by future space gravitational wave antennas. On the other hand, when the dark pion is the SIMP dark matter with the constraints for the chiral perturbative limit and pion-pion scattering cross section, the chiral phase transition becomes crossover and then the gravitational waves are not produced.« less

Early dust formation and a massive progenitor for SN 2011ja?

NASA Astrophysics Data System (ADS)

Andrews, J. E.; Krafton, Kelsie M.; Clayton, Geoffrey C.; Montiel, E.; Wesson, R.; Sugerman, Ben E. K.; Barlow, M. J.; Matsuura, M.; Drass, H.

2016-04-01

SN 2011ja was a bright (I = -18.3) Type II supernova occurring in the nearby edge on spiral galaxy NGC 4945. Flat-topped and multipeaked H α and H β spectral emission lines appear between 64 and 84 d post-explosion, indicating interaction with a disc-like circumstellar medium inclined ˜45° from edge-on. After day 84, an increase in the H- and K-band flux along with heavy attenuation of the red wing of the emission lines are strong indications of early dust formation, likely located in the cool dense shell created between the forward shock of the SN ejecta and the reverse shock created as the ejecta plows into the existing circumstellar material. Radiative transfer modelling reveals both ≈1 × 10-5 M⊙ of pre-existing dust located ˜1016.7 cm away and up to ≈6 × 10-4 M⊙ of newly formed dust. Spectral observations after 1.5 yr reveal the possibility that the fading SN is located within a young (3-6 Myr) massive stellar cluster, which when combined with tentative 56Ni mass estimates of 0.2 M⊙ may indicate a massive (≥25 M⊙) progenitor for SN 2011ja.

Dynamic Three-Dimensional Shoulder Mri during Active Motion for Investigation of Rotator Cuff Diseases.

PubMed

Tempelaere, Christine; Pierrart, Jérome; Lefèvre-Colau, Marie-Martine; Vuillemin, Valérie; Cuénod, Charles-André; Hansen, Ulrich; Mir, Olivier; Skalli, Wafa; Gregory, Thomas

2016-01-01

MRI is the standard methodology in diagnosis of rotator cuff diseases. However, many patients continue to have pain despite treatment, and MRI of a static unloaded shoulder seems insufficient for best diagnosis and treatment. This study evaluated if Dynamic MRI provides novel kinematic data that can be used to improve the understanding, diagnosis and best treatment of rotator cuff diseases. Dynamic MRI provided real-time 3D image series and was used to measure changes in the width of subacromial space, superior-inferior translation and anterior-posterior translation of the humeral head relative to the glenoid during active abduction. These measures were investigated for consistency with the rotator cuff diseases classifications from standard MRI. The study included: 4 shoulders with massive rotator cuff tears, 5 shoulders with an isolated full-thickness supraspinatus tear, 5 shoulders with tendinopathy and 6 normal shoulders. A change in the width of subacromial space greater than 4mm differentiated between rotator cuff diseases with tendon tears (massive cuff tears and supraspinatus tear) and without tears (tendinopathy) (p = 0.012). The range of the superior-inferior translation was higher in the massive cuff tears group (6.4mm) than in normals (3.4mm) (p = 0.02). The range of the anterior-posterior translation was higher in the massive cuff tears (9.2 mm) and supraspinatus tear (9.3 mm) shoulders compared to normals (3.5mm) and tendinopathy (4.8mm) shoulders (p = 0.05). The Dynamic MRI enabled a novel measure; 'Looseness', i.e. the translation of the humeral head on the glenoid during an abduction cycle. Looseness was better able at differentiating different forms of rotator cuff disease than a simple static measure of relative glenohumeral position.

Dynamic Three-Dimensional Shoulder Mri during Active Motion for Investigation of Rotator Cuff Diseases

PubMed Central

Tempelaere, Christine; Pierrart, Jérome; Lefèvre-Colau, Marie-Martine; Vuillemin, Valérie; Cuénod, Charles-André; Hansen, Ulrich; Mir, Olivier; Skalli, Wafa; Gregory, Thomas

2016-01-01

Background MRI is the standard methodology in diagnosis of rotator cuff diseases. However, many patients continue to have pain despite treatment, and MRI of a static unloaded shoulder seems insufficient for best diagnosis and treatment. This study evaluated if Dynamic MRI provides novel kinematic data that can be used to improve the understanding, diagnosis and best treatment of rotator cuff diseases. Methods Dynamic MRI provided real-time 3D image series and was used to measure changes in the width of subacromial space, superior-inferior translation and anterior-posterior translation of the humeral head relative to the glenoid during active abduction. These measures were investigated for consistency with the rotator cuff diseases classifications from standard MRI. Results The study included: 4 shoulders with massive rotator cuff tears, 5 shoulders with an isolated full-thickness supraspinatus tear, 5 shoulders with tendinopathy and 6 normal shoulders. A change in the width of subacromial space greater than 4mm differentiated between rotator cuff diseases with tendon tears (massive cuff tears and supraspinatus tear) and without tears (tendinopathy) (p = 0.012). The range of the superior-inferior translation was higher in the massive cuff tears group (6.4mm) than in normals (3.4mm) (p = 0.02). The range of the anterior-posterior translation was higher in the massive cuff tears (9.2 mm) and supraspinatus tear (9.3 mm) shoulders compared to normals (3.5mm) and tendinopathy (4.8mm) shoulders (p = 0.05). Conclusion The Dynamic MRI enabled a novel measure; ‘Looseness’, i.e. the translation of the humeral head on the glenoid during an abduction cycle. Looseness was better able at differentiating different forms of rotator cuff disease than a simple static measure of relative glenohumeral position. PMID:27434235

Uncemented three-dimensional-printed prosthetic reconstruction for massive bone defects of the proximal tibia.

PubMed

Lu, Minxun; Li, Yongjiang; Luo, Yi; Zhang, Wenli; Zhou, Yong; Tu, Chongqi

2018-03-06

Currently, it is challenging to treat massive bone defects of proximal tibia. Although numerous methods are available for reconstruction with epiphysis preservation, limitations in knee function and complications are noted with these methods. Our paper describes our attempt to reconstruct a marked defect in the proximal tibia with an uncemented three-dimensional (3D)-printed prosthesis and to evaluate the prosthesis design and short-term outcomes. A 15-year-old boy with metaphyseal osteosarcoma of the tibia underwent intercalary allograft reconstruction following wide tumour resection with epiphysis preservation. However, chronic allograft rejection and/or infection occurred after the surgery and a sinus tract was formed. The rejection and/or infection process was successfully stopped by the removal of the graft and implantation of an antibiotic-loaded cement spacer; however, the limb function was poor. Because of the irregular shape of the defect and the excessively short length of the residual proximal tibia, we used the 3D printing technology to design and fabricate a personalised prosthesis to reconstruct the defect, with the preservation of the knee joint. At the last follow-up at 26 months, the patient had satisfactory limb function. The 3D-printed prosthesis may be a feasible option in the reconstruction of tibial metaphyseal defects with the preservation of the knee joint. Moreover, it can result in good postoperative function and low complication rates. However, a long-term follow-up is required to clarify its long-term outcomes.

Constraining the Properties of the Eta Carinae System via 3-D SPH Models of Space-Based Observations: The Absolute Orientation of the Binary Orbit

NASA Technical Reports Server (NTRS)

Madura, Thomas I.; Gull, Theodore R.; Owocki, Stanley P.; Okazaki, Atsuo T.; Russell, Christopher M. P.

2011-01-01

The extremely massive (> 90 Stellar Mass) and luminous (= 5 x 10(exp 6) Stellar Luminosity) star Eta Carinae, with its spectacular bipolar "Homunculus" nebula, comprises one of the most remarkable and intensely observed stellar systems in the Galaxy. However, many of its underlying physical parameters remain unknown. Multiwavelength variations observed to occur every 5.54 years are interpreted as being due to the collision of a massive wind from the primary star with the fast, less dense wind of a hot companion star in a highly elliptical (e approx. 0.9) orbit. Using three-dimensional (3-D) Smoothed Particle Hydrodynamics (SPH) simulations of the binary wind-wind collision, together with radiative transfer codes, we compute synthetic spectral images of [Fe III] emission line structures and compare them to existing Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS) observations. We are thus able, for the first time, to tightly constrain the absolute orientation of the binary orbit on the sky. An orbit with an inclination of approx. 40deg, an argument of periapsis omega approx. 255deg, and a projected orbital axis with a position angle of approx. 312deg east of north provides the best fit to the observations, implying that the orbital axis is closely aligned in 3-D space with the Homunculus symmetry axis, and that the companion star orbits clockwise on the sky relative to the primary.

High Genetic Diversity of Measles Virus, World Health Organization European Region, 2005–2006

PubMed Central

Brown, Kevin E.; Jin, Li; Santibanez, Sabine; Shulga, Sergey V.; Aboudy, Yair; Demchyshyna, Irina V.; Djemileva, Sultana; Echevarria, Juan E.; Featherstone, David F.; Hukic, Mirsada; Johansen, Kari; Litwinska, Bogumila; Lopareva, Elena; Lupulescu, Emilia; Mentis, Andreas; Mihneva, Zefira; Mosquera, Maria M.; Muscat, Mark; Naumova, M.A.; Nedeljkovic, Jasminka; Nekrasova, Ljubov S.; Magurano, Fabio; Fortuna, Claudia; Rebelo de Andrade, Helena; Richard, Jean-Luc; Robo, Alma; Rota, Paul A.; Samoilovich, Elena O.; Sarv, Inna; Semeiko, Galina V.; Shugayev, Nazim; Utegenova, Elmira S.; van Binnendijk, Rob; Vinner, Lasse; Waku-Kouomou, Diane; Wild, T. Fabian; Brown, David W.G.; Mankertz, Annette; Muller, Claude P.; Mulders, Mick N.

2008-01-01

During 2005–2006, nine measles virus (MV) genotypes were identified throughout the World Health Organization European Region. All major epidemics were associated with genotypes D4, D6, and B3. Other genotypes (B2, D5, D8, D9, G2, and H1) were only found in limited numbers of cases after importation from other continents. The genetic diversity of endemic D6 strains was low; genotypes C2 and D7, circulating in Europe until recent years, were no longer identified. The transmission chains of several indigenous MV strains may thus have been interrupted by enhanced vaccination. However, multiple importations from Africa and Asia and virus introduction into highly mobile and unvaccinated communities caused a massive spread of D4 and B3 strains throughout much of the region. Thus, despite the reduction of endemic MV circulation, importation of MV from other continents caused prolonged circulation and large outbreaks after their introduction into unvaccinated and highly mobile communities. PMID:18258089

The formation of the Milky Way halo and its dwarf satellites; a NLTE-1D abundance analysis. II. Early chemical enrichment

NASA Astrophysics Data System (ADS)

Mashonkina, L.; Jablonka, P.; Sitnova, T.; Pakhomov, Yu.; North, P.

2017-12-01

We present the non-local thermodynamic equilibrium (NLTE) abundances of up to 10 chemical species in a sample of 59 very metal-poor (VMP, -4 ≤ [Fe/H] ≾-2) stars in seven dwarf spheroidal galaxies (dSphs) and in the Milky Way (MW) halo. Our results are based on high-resolution spectroscopic datasets and homogeneous and accurate atmospheric parameters determined in Paper I. We show that once the NLTE effects are properly taken into account, all massive galaxies in our sample, that is, the MW halo and the classical dSphs Sculptor, Ursa Minor, Sextans, and Fornax, reveal a similar plateau at [α/Fe] ≃ 0.3 for each of the α-process elements: Mg, Ca, and Ti. We put on a firm ground the evidence for a decline in α/Fe with increasing metallicity in the Boötes I ultra-faint dwarf galaxy (UFD), that is most probably due to the ejecta of type Ia supernovae. For Na/Fe, Na/Mg, and Al/Mg, the MW halo and all dSphs reveal indistinguishable trends with metallicity, suggesting that the processes of Na and Al synthesis are identical in all systems, independent of their mass. The dichotomy in the [Sr/Ba] versus [Ba/H] diagram is observed in the classical dSphs, similarly to the MW halo, calling for two different nucleosynthesis channels for Sr. We show that Sr in the massive galaxies is well correlated with Mg suggesting a strong link to massive stars and that its origin is essentially independent of Ba, for most of the [Ba/H] range. Our three UFDs, that is Boötes I, UMa II, and Leo IV, are depleted in Sr and Ba relative to Fe and Mg, with very similar ratios of [Sr/Mg] ≃-1.3 and [Ba/Mg] ≃-1 on the entire range of their Mg abundances. The subsolar Sr/Ba ratios of Boötes I and UMa II indicate a common r-process origin of their neutron-capture elements. Sculptor remains the classical dSph, in which the evidence for inhomogeneous mixing in the early evolution stage, at [Fe/H] <-2, is the strongest. Full Tables 3 and 4 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/608/A89

Development of iterative techniques for the solution of unsteady compressible viscous flows

NASA Technical Reports Server (NTRS)

Hixon, Duane; Sankar, L. N.

1993-01-01

During the past two decades, there has been significant progress in the field of numerical simulation of unsteady compressible viscous flows. At present, a variety of solution techniques exist such as the transonic small disturbance analyses (TSD), transonic full potential equation-based methods, unsteady Euler solvers, and unsteady Navier-Stokes solvers. These advances have been made possible by developments in three areas: (1) improved numerical algorithms; (2) automation of body-fitted grid generation schemes; and (3) advanced computer architectures with vector processing and massively parallel processing features. In this work, the GMRES scheme has been considered as a candidate for acceleration of a Newton iteration time marching scheme for unsteady 2-D and 3-D compressible viscous flow calculation; from preliminary calculations, this will provide up to a 65 percent reduction in the computer time requirements over the existing class of explicit and implicit time marching schemes. The proposed method has ben tested on structured grids, but is flexible enough for extension to unstructured grids. The described scheme has been tested only on the current generation of vector processor architecture of the Cray Y/MP class, but should be suitable for adaptation to massively parallel machines.

Massive Black Hole Mergers: Can we see what LISA will hear?

NASA Technical Reports Server (NTRS)

Centrella, Joan

2009-01-01

Coalescing massive black hole binaries are formed when galaxies merge. The final stages of this coalescence produce strong gravitational wave signals that can be detected by the space-borne LISA. When the black holes merge in the presence of gas and magnetic fields, various types of electromagnetic signals may also be produced. Modeling such electromagnetic counterparts requires evolving the behavior of both gas and fields in the strong-field regions around the black holes. We have taken a first step towards this problem by mapping the flow of pressureless matter in the dynamic, 3-D general relativistic spacetime around the merging black holes. We report on the results of these initial simulations and discuss their likely importance for future hydrodynamical simulations.

3D documenatation of the petalaindera: digital heritage preservation methods using 3D laser scanner and photogrammetry

NASA Astrophysics Data System (ADS)

Sharif, Harlina Md; Hazumi, Hazman; Hafizuddin Meli, Rafiq

2018-01-01

3D imaging technologies have undergone massive revolution in recent years. Despite this rapid development, documentation of 3D cultural assets in Malaysia is still very much reliant upon conventional techniques such as measured drawings and manual photogrammetry. There is very little progress towards exploring new methods or advanced technologies to convert 3D cultural assets into 3D visual representation and visualization models that are easily accessible for information sharing. In recent years, however, the advent of computer vision (CV) algorithms make it possible to reconstruct 3D geometry of objects by using image sequences from digital cameras, which are then processed by web services and freeware applications. This paper presents a completed stage of an exploratory study that investigates the potentials of using CV automated image-based open-source software and web services to reconstruct and replicate cultural assets. By selecting an intricate wooden boat, Petalaindera, this study attempts to evaluate the efficiency of CV systems and compare it with the application of 3D laser scanning, which is known for its accuracy, efficiency and high cost. The final aim of this study is to compare the visual accuracy of 3D models generated by CV system, and 3D models produced by 3D scanning and manual photogrammetry for an intricate subject such as the Petalaindera. The final objective is to explore cost-effective methods that could provide fundamental guidelines on the best practice approach for digital heritage in Malaysia.

Hawking radiation via anomaly cancellation for the black holes of five-dimensional minimal gauged supergravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Porfyriadis, Achilleas P.

2009-04-15

The anomaly cancellation method proposed by Wilczek et al. is applied to the general charged rotating black holes in five-dimensional minimal gauged supergravity. Thus Hawking temperature and fluxes are found. The Hawking temperature obtained agrees with the surface gravity formula. The black holes have charge and two unequal angular momenta, and these give rise to appropriate terms in the effective U(1) gauge field of the reduced (1+1)-dimensional theory. In particular, it is found that the terms in this U(1) gauge field correspond exactly to the correct electrostatic potential and the two angular velocities on the horizon of the black holes,more » and so the results for the Hawking fluxes derived here from the anomaly cancellation method are in complete agreement with the ones obtained from integrating the Planck distribution.« less

Geometric U-folds in four dimensions

NASA Astrophysics Data System (ADS)

Lazaroiu, C. I.; Shahbazi, C. S.

2018-01-01

We describe a general construction of geometric U-folds compatible with a non-trivial extension of the global formulation of four-dimensional extended supergravity on a differentiable spin manifold. The topology of geometric U-folds depends on certain flat fiber bundles which encode how supergravity fields are globally glued together. We show that smooth non-trivial U-folds of this type can exist only in theories where both the scalar and space-time manifolds have non-trivial fundamental group and in addition the scalar map of the solution is homotopically non-trivial. Consistency with string theory requires smooth geometric U-folds to be glued using subgroups of the effective discrete U-duality group, implying that the fundamental group of the scalar manifold of such solutions must be a subgroup of the latter. We construct simple examples of geometric U-folds in a generalization of the axion-dilaton model of \

3D numerical calculations and synthetic observations of magnetized massive dense core collapse and fragmentation.

NASA Astrophysics Data System (ADS)

Commerçon, B.; Hennebelle, P.; Levrier, F.; Launhardt, R.; Henning, Th.

2012-03-01

I will present radiation-magneto-hydrodynamics calculations of low-mass and massive dense core collapse, focusing on the first collapse and the first hydrostatic core (first Larson core) formation. The influence of magnetic field and initial mass on the fragmentation properties will be investigated. In the first part reporting low mass dense core collapse calculations, synthetic observations of spectral energy distributions will be derived, as well as classical observational quantities such as bolometric temperature and luminosity. I will show how the dust continuum can help to target first hydrostatic cores and to state about the nature of VeLLOs. Last, I will present synthetic ALMA observation predictions of first hydrostatic cores which may give an answer, if not definitive, to the fragmentation issue at the early Class 0 stage. In the second part, I will report the results of radiation-magneto-hydrodynamics calculations in the context of high mass star formation, using for the first time a self-consistent model for photon emission (i.e. via thermal emission and in radiative shocks) and with the high resolution necessary to resolve properly magnetic braking effects and radiative shocks on scales <100 AU (Commercon, Hennebelle & Henning ApJL 2011). In this study, we investigate the combined effects of magnetic field, turbulence, and radiative transfer on the early phases of the collapse and the fragmentation of massive dense cores (M=100 M_⊙). We identify a new mechanism that inhibits initial fragmentation of massive dense cores, where magnetic field and radiative transfer interplay. We show that this interplay becomes stronger as the magnetic field strength increases. We speculate that highly magnetized massive dense cores are good candidates for isolated massive star formation, while moderately magnetized massive dense cores are more appropriate to form OB associations or small star clusters. Finally we will also present synthetic observations of these collapsing massive dense cores.

3D Printing of Organs-On-Chips

PubMed Central

Yi, Hee-Gyeong; Lee, Hyungseok; Cho, Dong-Woo

2017-01-01

Organ-on-a-chip engineering aims to create artificial living organs that mimic the complex and physiological responses of real organs, in order to test drugs by precisely manipulating the cells and their microenvironments. To achieve this, the artificial organs should to be microfabricated with an extracellular matrix (ECM) and various types of cells, and should recapitulate morphogenesis, cell differentiation, and functions according to the native organ. A promising strategy is 3D printing, which precisely controls the spatial distribution and layer-by-layer assembly of cells, ECMs, and other biomaterials. Owing to this unique advantage, integration of 3D printing into organ-on-a-chip engineering can facilitate the creation of micro-organs with heterogeneity, a desired 3D cellular arrangement, tissue-specific functions, or even cyclic movement within a microfluidic device. Moreover, fully 3D-printed organs-on-chips more easily incorporate other mechanical and electrical components with the chips, and can be commercialized via automated massive production. Herein, we discuss the recent advances and the potential of 3D cell-printing technology in engineering organs-on-chips, and provides the future perspectives of this technology to establish the highly reliable and useful drug-screening platforms. PMID:28952489

3D Printing of Organs-On-Chips.

PubMed

Yi, Hee-Gyeong; Lee, Hyungseok; Cho, Dong-Woo

2017-01-25

Organ-on-a-chip engineering aims to create artificial living organs that mimic the complex and physiological responses of real organs, in order to test drugs by precisely manipulating the cells and their microenvironments. To achieve this, the artificial organs should to be microfabricated with an extracellular matrix (ECM) and various types of cells, and should recapitulate morphogenesis, cell differentiation, and functions according to the native organ. A promising strategy is 3D printing, which precisely controls the spatial distribution and layer-by-layer assembly of cells, ECMs, and other biomaterials. Owing to this unique advantage, integration of 3D printing into organ-on-a-chip engineering can facilitate the creation of micro-organs with heterogeneity, a desired 3D cellular arrangement, tissue-specific functions, or even cyclic movement within a microfluidic device. Moreover, fully 3D-printed organs-on-chips more easily incorporate other mechanical and electrical components with the chips, and can be commercialized via automated massive production. Herein, we discuss the recent advances and the potential of 3D cell-printing technology in engineering organs-on-chips, and provides the future perspectives of this technology to establish the highly reliable and useful drug-screening platforms.

Black hole attractors and gauge theories

NASA Astrophysics Data System (ADS)

Huang, Lisa Li Fang

2007-12-01

This thesis is devoted to the study of supersymmetric black holes that arise from string compactifications. We begin by studying the R 2 corrections to the entropy of two solutions of five dimensional supergravity, the supersymmetric black ring and the spinning black hole. Using Wald's formula we compute the R2 corrections to the entropy of the black ring and BMPV black hole. We study N D4-branes wrapping a 4 cycle and M DO-branes on the quintic. For N D4-branes, we resolve the naive mismatch between the moduli space of the Higgs branch of the gauge theory and the moduli of a degree N hypersurface which the D4-brane wraps. The degree N surface must admit a holomorphic divisor and is a determinantal variety. Adding a single DO brane to probe the deformed geometry, we recover the determinant equation from F and D flatness condition which was previously discovered from a classical geometry approach. We next generalize the qunitic story for Calabi-Yau manifolds arising from complete intersections in toric varieties. We recover the moduli space of N D4-branes in terms of the moduli space of a U( N) x U(N) gauge theory with bi-fundamentals com ing from a D6 - D6 system. We also recast the tachyon condensation of the D6 - D6 system in the language of open string gauged linear sigma model. We obtain the determinant equation from F-term constraints arising from a boundary coupling. We set out to understand the Ooguri-Strominger-Vafa conjecture directly in the D4-DO black hole attractor geometry. We show that the lift to the euclidean IIA attractor geometry gives a complexified M-theory geometry whose asymptotic boundary is a torus. Employing AdS3/CFT 2 duality, we argue that the string partition function computes the elliptic genus of the Maldacena-Strominger-Witten conformal field theory. We evaluate the IIA partition function using the Green-Schwarz formalism and show that it gives ZtopZ top, coming from instantons and anti-instantons respectively. Finally, we determine the spectrum of free, large N, SU( N) Yang Mills theory on S3 by decomposing its thermal partition function into characters of the irreducible representations of the conformal group SO(4, 2).

Vitamin D as Supplemental Therapy for Pneumocystis Pneumonia.

PubMed

Lei, Guang-Sheng; Zhang, Chen; Zimmerman, Michelle K; Lee, Chao-Hung

2015-12-14

The combination of all-trans retinoic acid (ATRA) and primaquine (PMQ) has been shown to be effective for therapy of Pneumocystis pneumonia (PCP). Since a high concentration of ATRA has significant adverse effects, the possibility that vitamin D can be used to replace ATRA for PCP therapy was investigated. C57BL/6 mice were immunosuppressed by depleting CD4(+) cells and infected with Pneumocystis murina 1 week after initiation of immunosuppression. Three weeks after infection, the mice were treated orally for 3 weeks with vitamin D3 (VitD3) alone, PMQ alone, a combination of VitD3 and PMQ (VitD3-PMQ), or a combination of trimethoprim and sulfamethoxazole (TMP-SMX). Results showed that VitD3 (300 IU/kg/day) had a synergistic effect with PMQ (5 mg/kg/day) for therapy of PCP. Flow cytometric studies showed that this VitD3-PMQ combination recovered the CD11b(low) CD11c(high) alveolar macrophage population in mice with PCP as effectively as TMP-SMX. The VitD3-PMQ combination also reduced the massive infiltration of inflammatory cells into the lungs and the severity of lung damage. VitD3 was also shown to reduce the dose of TMP-SMX required for effective treatment of PCP. Taken together, results of this study suggest that a VitD3-PMQ combination can be used as an alternative therapy for PCP. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Graviton mass or cosmological constant?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gabadadze, Gregory; Gruzinov, Andrei

2005-12-15

To describe a massive graviton in 4D Minkowski space-time one introduces a quadratic term in the Lagrangian. This term, however, can lead to a readjustment or instability of the background instead of describing a massive graviton on flat space. We show that for all local 4D Lorentz-invariant mass terms Minkowski space is unstable. The instability can develop in a time scale that is many orders of magnitude shorter than the inverse graviton mass. We start with the Pauli-Fierz (PF) term that is the only local mass term with no ghosts in the linearized approximation. We show that nonlinear completions ofmore » the PF Lagrangian give rise to instability of Minkowski space. We continue with the mass terms that are not of a PF type. Although these models are known to have ghosts in the linearized approximations, nonlinear interactions can lead to background change in which the ghosts are eliminated. In the latter case, however, the graviton perturbations on the new background are not massive. We argue that a consistent theory of a massive graviton on flat space can be formulated in theories with extra dimensions. They require an infinite number of fields or nonlocal description from a 4D point of view.« less

Massive Symbolic Mathematical Computations and Their Applications

DTIC Science & Technology

1988-08-16

NUMBER ORGANIZATION (if appi cable) AFOSR I A_ /__ I F49620-87- C -0113 Bc. ADDRESS (City, Stare, and ZIP Code) %. SOURCE OF FUNDING NUMBERS PROGRAM PROJECT...TASK WORK UNIT - < ’/I/ "//ELEMENT NO. NO. NO. ACCESSION NO. /,, AF,; c 9r ;- 6 (4/tL’ " ’ ’! /K’, 11 TITLE (Incoue Secuirty Classification) Massive...DARPA R & D Status Report AFOSR.m. 8 8-1 12Contract No. F49620-87- C -0113 MASSIVE SYMBOLIC MATHEMATICAL COMPUTATIONS AND THEIR APPLICATIONS Quarterly

WW Geminorum: An Early B-type Eclipsing Binary Evolving into the Contact Phase

NASA Astrophysics Data System (ADS)

Yang, Y.-G.; Yang, Y.; Dai, H.-F.; Yin, X.-G.

2014-11-01

WW Gem is a B-type eclipsing binary with a period of 1.2378 days. The CCD photometry of this binary was performed in 2013 December using the 85 cm telescope at the Xinglong Stations of the National Astronomical Observatories of China. Using the updated W-D program, the photometric model was deduced from the VRI light curves. The results imply that WW Gem is a near-contact eclipsing binary whose primary component almost fills its Roche lobe. The photometric mass ratio is q ph = 0.48(± 0.05). All collected times of minimum light, including two new ones, were used for the period studies. The orbital period changes of WW Gem could be described by an upward parabola, possibly overlaid by a light-time orbit with a period of P mod = 7.41(± 0.04) yr and a semi-amplitude of A = 0.0079 days(± 0.0005 days), respectively. This kind of cyclic oscillation may be attributed to the light-travel time effect via the third body. The long-term period increases at a rate of dP/dt = +3.47(±0.04) × 10-8 day yr-1, which may be explained by the conserved mass transfer from the less massive component to the more massive one. With mass transfer, the massive binary WW Gem may be evolving into a contact binary.

A hydrodynamical model of the circumstellar bubble created by two massive stars

NASA Astrophysics Data System (ADS)

van Marle, A. J.; Meliani, Z.; Marcowith, A.

2012-05-01

Context. Numerical models of the wind-blown bubble of massive stars usually only account for the wind of a single star. However, since massive stars are usually formed in clusters, it would be more realistic to follow the evolution of a bubble created by several stars. Aims: We develop a two-dimensional (2D) model of the circumstellar bubble created by two massive stars, a 40 M⊙ star and a 25 M⊙ star, and follow its evolution. The stars are separated by approximately 16 pc and surrounded by a cold medium with a density of 20 particles per cm3. Methods: We use the MPI-AMRVAC hydrodynamics code to solve the conservation equations of hydrodynamics on a 2D cylindrical grid using time-dependent models for the wind parameters of the two stars. At the end of the stellar evolution (4.5 and 7.0 million years for the 40 and 25 M⊙ stars, respectively), we simulate the supernova explosion of each star. Results: Each star initially creates its own bubble. However, as the bubbles expand they merge, creating a combined, aspherical bubble. The combined bubble evolves over time, influenced by the stellar winds and supernova explosions. Conclusions: The evolution of a wind-blown bubble created by two stars deviates from that of the bubbles around single stars. In particular, once one of the stars has exploded, the bubble is too large for the wind of the remaining star to maintain and the outer shell starts to disintegrate. The lack of thermal pressure inside the bubble also changes the behavior of circumstellar features close to the remaining star. The supernovae are contained inside the bubble, which reflects part of the energy back into the circumstellar medium. Movies are available in electronic form at http://www.aanda.org

Star products on graded manifolds and α′-corrections to Courant algebroids from string theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deser, Andreas, E-mail: andreas.deser@itp.uni-hannover.de

2015-09-15

Courant algebroids, originally used to study integrability conditions for Dirac structures, have turned out to be of central importance to study the effective supergravity limit of string theory. The search for a geometric description of T-duality leads to Double Field Theory (DFT), whose gauge algebra is governed by the C-bracket, a generalization of the Courant bracket in the sense that it reduces to the latter by solving a specific constraint. Recently, in DFT deformations of the C-bracket and O(d, d)-invariant bilinear form to first order in the closed string sigma model coupling, α′ were derived by analyzing the transformation propertiesmore » of the Neveu-Schwarz B-field. By choosing a particular Poisson structure on the Drinfel’d double corresponding to the Courant algebroid structure of the generalized tangent bundle, we are able to interpret the C-bracket and bilinear form in terms of Poisson brackets. As a result, we reproduce the α′-deformations for a specific solution to the strong constraint of DFT as expansion of a graded version of the Moyal-Weyl star product.« less

A Survey of Parallel Computing

DTIC Science & Technology

1988-07-01

Evaluating Two Massively Parallel Machines. Communications of the ACM .9, , , 176 BIBLIOGRAPHY 29, 8 (August), pp. 752-758. Gajski , D.D., Padua, D.A., Kuck...Computer Architecture, edited by Gajski , D. D., Milutinovic, V. M. Siegel, H. J. and Furht, B. P. IEEE Computer Society Press, Washington, D.C., pp. 387-407

Core-collapse supernova simulations

NASA Astrophysics Data System (ADS)

Mueller, Bernhard

2017-01-01

Core-collapse supernovae, the deaths of massive stars, are among the most spectacular phenomena in astrophysics: Not only can supernovae outshine their host galaxy for weeks; they are also laboratories for the behavior of matter at supranuclear densities, and one of the few environments where collective neutrino effects can become important. Moreover, supernovae play a central role in the cosmic matter cycle, e.g., as the dominant producers of oxygen in the Universe. Yet the mechanism by which massive stars explode has eluded us for decades, partly because classical astronomical observations across the electromagnetic spectrum cannot directly probe the supernovae ``engine''. Numerical simulations are thus our primary tool for understanding the explosion mechanism(s) of massive stars. Rigorous modeling needs to take a host of important physical ingredients into account, such as the emission and partial reabsorption of neutrinos from the young proto-neutron star, multi-dimensional fluid motions, general relativistic gravity, the equation of state of nuclear matter, and magnetic fields. This is a challenging multi-physics problem that has not been fully solved yet. Nonetheless, as I shall argue in this talk, recent first-principle 3D simulations have gone a long way towards demonstrating the viability of the most popular explosion scenario, the ``neutrino-driven mechanism''. Focusing on successful explosion models of the MPA-QUB-Monash collaboration, I will discuss possible requirements for robust explosions across a wide range of progenitors, such as accurate neutrino opacities, stellar rotation, and seed asymmetries from convective shell burning. With the advent of successful explosion models, supernova theory can also be confronted with astronomical observations. I will show that recent 3D models come closer to matching observed explosion parameters (explosion energies, neutron star kicks) than older 2D models, although there are still discrepancies. This work has been supported by the ARC (grant DE150101145), NSF (PHY-1430152, JINA-CEE) and the supercomputing centers/initiatives NCI, Pawsey, and DiRAC.